Of Angels, Demons & Spirits

Mankad

Spirit schmirit. It’s the law, is it not?

To paraphrase Meatloaf, stop right there, I need to know right now…before you go any further, do you expect this post to pontificate and decide whether what the West Indian bowler did today on the last ball of their U19 World Cup game against Zimbabwe right? If yes, I am sorry to disappoint you. This post will not dwell on that, though it has been triggered by the reactions that incident solicited.

Those reactions have been seen before – during Jos Buttler’s dismissal, during the Ian Bell incident, for Inzamam Ul Haq, and even during Underarmgate. To cite a different sport, something similar happened in Game 3 of the World Series between the Boston Red Sox and the Detroit Tigers. A friend of mine and fellow blogger wrote this piece about how the spirit of cricket is nonsense and should be done away with. His anger is not directed at the idea that people in a competitive arena can be sometimes (and are often) touched by the better angels of their nature and do what ‘feels right.’ His anger is directed at the hypocrisy every such event exposes where self professed defenders of the ‘spirit of the game’ go all righteous about something that is not illegal as per the laws that govern the game. My friend should know. He is a lawyer.

But that’s another thing about laws – ever since they have existed in any sphere in life, there has been an eternal battle between the letter of the law and its spirit. Everyone sneers at those who exploit a loophole in a law for their advantage but is quick to rush to do so themselves if given the opportunity. But isn’t every bit of incremental advantage important when you are in a high stakes competition? The idea of ‘spirit’ exists in this grey zone between what’s legal and what’s not which is why it is hard to judge a violation  of it or even more fundamentally, it’s very existence.

Sports, as a human endeavor, has mixed history in terms of whether it is a tool that builds character or one that merely reveals our true self. In 1987 when Courtney Walsh refused to Mankad Pakistan No. 11 Saleem Jaffar, he was hailed precisely because we did not expect him to do that. With 2 to win for Pakistan off the last ball and a semi final place at stake, we expected him to take that incremental advantage that was available to him. Maradona punching the ball in against England in 1986 did that.

There are many laws across sports where they are open to interpretation and consequently potential abuse. There is a rule in tennis about time taken by players between points but umpires are often discretionary about it considering the flow of the game. When Novak Djokovic became notorious for overshooting those lax time limits in the name of bouncing the ball a gazillion times before serving, they did intervene. Golf too relies on such generous interpretations at times. As Mark Twain once put it ‘It’s good sportsmanship to not pick up lost golf balls while they are still rolling.’ As long as there is room for interpretation the question about whether or not spirit should play a role will never be settled.

I had gone to an exhibition at the Olympic Museum in Lausanne in 2005 called ‘Angels or Demons: The choice of fair play’. It looked at why people cheat in sport and what such behavior tells us about ourselves. I remember a line I had seen there – “Over the centuries, demons and angels alike have lost their independent reality. They have become powers inherent to the person, a symbol of his or her quest for perfection or of personal weaknesses.” The impression I came away with was that it ultimately was myriad factors that inclined someone to act one way or another where the rule left either real or perceived room for interpretation. Things are even more complex for context based individual situations like today’s.

That is precisely why now is not the time to have a debate about the spirit of cricket (or any other sport for that matter) by precipitating the whole debate on this one instance where a teenage kid did something perfectly within the rules during a high pressure situation. And like Lincoln had said in his inaugural address, we can always hold up hope that in the long run we can be touched in the sports arena or outside, by the better angels of our nature. Like Nicholas Hogg wrote on Cricinfo a while back – “Like religion, the Spirit of Cricket is a concept universally understood but not universally practised.” And those exceptions like a Courtney Walsh lend the appeal that the idea has.

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Decoding Djokovic’s Halo

Novak-Djokovic 16 Trophy

First they ignored him, then they ridiculed him, then they hated him, and then he won.

The last time I wrote about Novak Djokovic was in 2012 after THAT Australian Open final against Rafael Nadal. I had pointed out then how Djokovic’s remarkable success seems to stem from the fact that he does not take things too seriously but at the same time works very hard on his game. Four years is a long time in modern tennis. Since the Australian Open in 2012, Djokovic has won 6 more Grand Slams including this tournament 3 times. He has been at a peak level seldom seen in men’s tennis in the Open Era just falling short of a calendar Grand Slam in 2015. Except for the Australian Open in 2014, he has not done worse than the semifinal in any Grand Slam since the 2010 French Open. By any standards that is exceptional.

In 2015 he was nearly invincible even when compared to greats in other sports that year.

Djoko’s 2015

W-L 82-6 (93%)

Grand Slams: Australian Open, Wimbledon, US Open

ATP Ranking Points earned: 16585 (most ever accumulated in a year, more than the No.2 and No.3 that year COMBINED)

Prize Money: $21 million (largest ever earned in a year)

His performance and consistency were so phenomenal people were running out of adjectives to describe them. Yet, somehow Djokovic never evoked the kind of flowery prose that flowed from sportswriters’ keyboards for Roger Federer or the respect that an assessment of Rafael Nadal in his prime commanded. Somehow in a Golden Age of men’s tennis where we swooned over the artistry of Federer’s Da Vinci or Nadal’s Michaelangelo had entered this impostor who did not as much do art as he painted by numbers. But he outshone his peers in a way that was unimaginable even when Djokovic had a breakout year in 2011 and that performance at the 2012 Australian Open where he beat Nadal.

So, what is the deal with Novak Djokovic? The once showboaty, standoffish player who used to grind opponents into exasperated submission with annoying tactics (his ridiculously long ball bouncing before his serve routine was particularly despised) now suddenly appears an island of calmness, composure, great skill and humility. Did the Djoker suddenly stop being an agent of chaos? Did the painter by numbers suddenly start producing brushstrokes of extreme beauty spontaneously? The short answer is no.

Djokovic never plays beautiful shots in the conventional meaning of the term. If a Federer’s backhand is the maple wood hand crafted Grand Piano, Djokovic’s is a note crafted on the piano app of Apple’s Garage Band software. Nadal’s aggression is a majestic Concorde to Djokovic’s quiet Airbus A300 like efficiency. Djokovic’s secret to success and the longevity of that success has been, well longevity. He learnt to outlast his opponents on the court. He was both physically and mentally impossible to tear down. A wrong call or a poor challenge could easily fluster Murray, even irk the usually dignified Federer, but not Djokovic. ESPN profiled his fitness regime in a 2012 article where Eli Saslow observed:

In his rise to the top of his sport, Djokovic has turned himself into a case study of what it now requires to be No. 1. Every detail is crucial. Every angle is considered. Every moment a chance to gain an incremental edge.

Dojokovic himself was asked this question after he had won his latest grand slam, the Australia Open 2016. He said he couldn’t “pick one thing and say that was the secret of success”

[I]t’s not that easy. If it’s that easy and simple and say one or two things, then I think many people would do it. It’s actually many years of obviously commitment, hard work, sacrifice and dedication, not just to training sessions, you know, the things that you are obliged to do as a tennis player, but also to a lifestyle. Trying to devote most of your time, energy, thought to make yourself the best person and the best player possible.

He has always been good at understanding that success on the court is paradoxically a complex mixture of things but also keeping things straightforward when on the court. So, while a Federer tries his SABR (Sneak Attack by Roger) or a Richard Gasquet almost exclusively deals in elegant backhands, and Angelique Kerber tries to get most value out of her drop shots,  Djokovic just looks at returning the ball deep into the opponents court and wait for them to make a mistake. He is one of the best of all time in absorbing pressure and turning defence into offence. He has built that patience and discipline in his game (and he himself admits that taking up Yoga has helped).

The problem is all these tiny bits add up insidiously, behind the scenes and there is no Grand Design to hold forth and celebrate Djokovic as a champion. Which is why he’s never been the easy crowd favourite. But even there he has built a wall brick by brick, winning fans over one tiny improvement at a time. Now his success has become the banner under which his popularity rides. As he himself says,“staying respectful to all my opponents and my colleagues and to this sport is a key to continue on and maintain this level of success and performance. I hope. This is kind of approach to help me to get to where I am. I don’t want to step away from it.”

Clearly Djokovic 2.0 has found an inner balance that comes not from detachment, but from blending the different facets of your life – professional and private. He said at the post match press conference after the 2016 Australia Open final, “you can’t separate yourself professionally and privately. You’re the same person. So all this emotions that are maybe trapped, you know, that occur in your private life, the issues, the problems that we all face, you need to surface them.”

His tennis might not be the most beautiful to watch, but that balance and humility he has cultivated certainly is.

I’ll leave you with Djokovic’s smile at the 2011 Australian Open and in 2016. See if you can spot the one which is of a man with a sense of inner balance.

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Dhonilytics

I don’t often write about physics here, but when I do it’s because I remember what my favorite physics teacher had told me – to keep find physics in the everyday. Given that I spend a heck of a lot of time following sports, everyday does turn out to be sports.

Eariler in the day today, Indian T20 captain and wicketkeeper M S Dhoni effected his 140th stumping, thus establishing a world record for most stumpings in international cricket matches (89 in ODIs, 13 in T20s and 38 in Tests).

In the T20 match between India and Australia at the MCG today, his first stumping of Glenn Maxwell off Yuvraj Singh was particularly impressive because he hardly had any reaction time. Cricket writer @Sampath_B24 posted a nice slow motion video of the dismissal with the claim that the reaction time was 0.1 seconds.

But Sampath was worried about the veracity of his number so I did a little bit of digging.

First, a quick primer on slow motion – essentially slow motion is video that was shot at a much faster rate (say a camera took 120 frames per second (fps) to construct a picture) but then played back at a much slower frame rate. Ordinary film is recorded at 24 fps so what we call video is really a set of pictures rapidly shuffling before us, much like a flipbook.

Remember Ishaan’s in Taare Zameen Par?

But if we play that back in slow motion we might find that there is a lot of blurring because pictures of high speed sporting action may have missed microsecond transitions.

The puzzle for me was to time how much time Dhoni had to react i.e. from the time the ball reached his gloves to him taking the bails off. Of course I had joked during the one day series where he made another smart stumping that:

Dhoni

But this had to pass scientific scrutiny. Unfortunately the broadcaster had not given us the reaction time (like they sometimes do when they show a good reflex catch being taken) but Sampath’s 16 second clip had enough clues to check at least crudely if his claim of 0.1 second was broadly correct.

I asked my go to physics person on twitter and he said sports cameras usually record at about 120 fps.

I confirmed that from an ABC page on how slow motion works and confirmed the general math with another article on baseball physics. So assuming the Channel 9 cameras covering the game at the MCG were recording at 120 fps (the broadcast standard) and playing it at 1/5 the speed (24 fps), the real time as compared to what you see in the video should be 5 times faster.

I timed Dhoni’s reaction time and on the slow-mo according to my stopwatch it was between 0.5-0.6 seconds (I did this three times to get an average number to round off errors). The real time then would be 0.5 or 0.6 divided by 5 which is roughly between 0.1-0.12 seconds.

I am happy to report that Sampath’s eyeballed claim more or less stands. As does the general claim that Dhoni is one of the best when it comes to reaction times behind the wicket.

Maybe someone can look at this a little more scientifically and analyze some Dhoni slomo videos. Or just hand a physics class a project. That should, as with anything Dhoni touches, make physics just a tad bit more  interesting.

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Thoughts on today

When I got up this morning, I was really excited and looking forward to watching some test cricket in Bangalore after a gap of three years. And then I read about Paris. Every act of terror sickens me to the core, the immediacy and juxtaposition of the events in Paris against my eagerness to catch the sporting action made it worse. There was a feeling of dread mixed with guilt gnawing at me, forcing me – some might think frivolously – to consider whether to go to the game or not. 

The terrorists had triggered a bomb just outside Stad De France as a France-Germany friendly was going on inside. All these details made it a terribly complicated morning. I have often used sport as a port in an emotional storm – I remember during one of my greatest moments of personal tragedy and loss, a friend hugged me tight and calmly whispered the news that India had qualified for the tri series final (this was in 1997). This was not his attempt to trivialise my tragedy; knowing me far too well, he knew I’d interpret this as code for ‘life goes on’. 

This morning, I did make it to the stadium partly because I had to hand tickets over to a couple of friends of mine, partly because I felt deep down that sport will provide some succour to that feeling in the pit of my stomach. I am not writing this to make any arguments about what happened in Paris (or for that matter in Beirut just two days ago and in Ankara two weeks back and so on); neither am I offering a point of view or pseudo-expertise comments on how to deal with this. I am only writing this as an intensely personal record of how I coped today. 

I went to watch a sporting event. One where the moment I was entering I noticed a lady from South Africa, toddler strapped to her back, and 6 year old son alongside also making her way to the stands. She stopped by at a street vendor and bought her son an India flag, encouraging him to wave it and smile at everyone around. One where as I took my seat South Africa were 15/2 and soon Varun Aaron bowled Hashim Amla with a beauty of a delivery to leave them at 45/3 and in walked A B DeVilliers playing his 100th Test Match. One where the entire crowd at the Chinnaswamy Stadium got to its feet spontaneously and clapped and chanted his name along with the standing ovation to welcome him to the crease. He was walking to the middle in the capacity of an adversary and South Africa’s key asset. And yet, there was so much love and warmth for him all through his innings. It was a remarkable sight, a testament to the unifying power that sport yields. 

That moment as DeVilliers walked out to the middle is what lent perspective to my sullen mood. No, it did not solve any problems. It did not make the terror and its horrors go away. But it was life affirming and it helped me cope. Just like that news of India making it to the final was, I interpreted this to be code for ‘life goes on’. 

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VIRU PAAJI, ME & THE GMAT

I don’t know about anyone else but besides the joy and thrill of watching Virender Sehwag bat, there was something I learnt from him that had a direct impact on my career. It was when I took my GMAT.

In the test it is a waste of effort to figure out if you got a question right or wrong. You do your best on every question and move on (in the GMAT you have to answer a question to get to the next question; there’s no skipping) and forget about the last question. That bit of mental block was erased when I realized that’s exactly how Virender Sehwag bats. He may have gotten beaten on the last delivery but it makes no difference to his approach to the next one. And that’s exactly what I hadn’t been doing while taking the practice tests!

So long, Viru! And thanks for the fish!

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Klopp-struck

It was almost as if a rock band had announced a new lead singer. Juergen Klopp’s appointment as Liverpool FC manager has justifiably amped up the atmosphere at Anfield and among the LFC faithful. For a club trudging along in mediocrity for the good part of a season and a half, its fans deserved a shot in the arm because despite Brendan Rodgers’ best intentions, passion was fading into prosaic passing and forlorn football at one of the world’s most storied clubs. 

As a Liverpool fan, I am obviously optimistic and excited about one of the most exciting managers in world football taking over. And while I have the ‘make us dream’ sentiment willing to leap right out, I also know that pragmatically it’s one baby step (or if you are Philippe Coutinho, one baby step over) at a time. And that is where Klopp’s broad philosophy and approach to football fills me with the hope that we will get to see what fans always want to see in their club. In the NBC show Men In Blazers, John Oliver, the host of HBO’s Last Week Tonight and Liverpool fan, had said that the only thing he expected from his team every single time was to see them play heartwarming and exciting football. Klopp looks like someone who could be positioned to give exactly that. It’s easy to buy into the personality cult of a manager these days (I am looking at you, Jose) but Klopp despite his outwardly rockstar-ness is a manager tethered to the reality of a high pressure job in a high pressure environment. That is why I was delighted to hear him say in the press conference that his aim was to see ‘fighting spirit, many sprints, many shots, and the result is the result of these things’. 

That was how it was during that dream run of 2013-14 when I used to switch on the TV set during a Liverpool game to experience pure joy at watching a Suarez rushing forward, a sublime Sturridge finish or a fine Sterling dribble. Circumstances have obviously changed since then but this appointment shows the club is willing to show ambition and dare to dream. Liverpool and its fans are often berated for piping on about their history with not much to show in the last quarter of a century. Klopp’s assertion that ‘history is the base for us’ and caution that ‘it’s not allowed to take history in the backpack’ is exactly the reassurance the fan in me wanted to hear. 

Here is a manager who is not willing to make boombastic statements but at the same time not given to platitudes and anodynes. Klopp showed a surprisingly good grasp of economics when he admitted about the information asymmetry that rules the players signing market (‘I’m not a genius. I need other people to get the perfect information. When we have this we will decide to sign or sell a player.’) And that is why I believe he is indeed the Normal One. 

And one hopes, with him at the helm, normal service resumes soon at Liverpool Football Club, when I can switch the TV on again every week knowing the metaphorical champagne will flow out of those high definition pixels. 

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The Physics of Bodyline

[This post is dedicate to my physics teacher at college, who always encouraged us to find joy in the physics of the everyday. He sadly passed away in 2012.]

The Bodyline series of 1932-33 where England skipper Douglas Jardine employed questionable tactics (at least for that time) of having his quick bowlers, specifically Harold Larwood, bowl bouncers at the body of the Australian batsmen in an attempt to contain them in general and Don Bradman in particular to win the Ashes back, is one of those divisive chapters in cricket that changed definitions of cricketing laws in both letter and spirit.

Newtonian Laws of motion weren't very kind on Australian batsmen in the summer of 1932-33

Newtonian Laws of motion weren’t very kind on Australian batsmen in the summer of 1932-33

However, this post is not about examining the social or cultural impact of Bodyline on the game. (Incidentally, I did that for the website cricking.com here.) This post is about examining the physics of the Bodyline tactics. Because cricket is as much about the laws laid down by the MCC as it is about Newton’s Laws of motion. Bodyline created such an upheaval that not only did purists think bouncers hurled at the batsman’s body at serious velocity would tear apart the fabric of the spirit of cricket, but maybe the more relativistic physics oriented among them feared that a cricket ball delivered close enough to the speed of light would tear a hole into the space-time continuum. As of now, the fastest recorded cricket delivery remains at around 100 miles per hour, thus keeping the current universe intact. But the physics is still interesting.


Technical note: For the sake of the casual reader who does not need the horror of high school physics triggered in them, I will be skipping formulas and calculations for the most part here, focusing on just the fundamentals; however, more technical treatment for similar ideas can be found here and here.


The whole Bodyline tactic, or Fast Leg Theory as Jardine called it rested on the idea of a bowler being able to hurl the cricket ball at a batsman’s body at pace and at an uncomfortable height (somewhere around the chest ideally) with a packed ring of fielders close on the leg side ready to pounce on catches if the batsman fended the delivery poorly with his bat. I checked Jardine’s educational background and he was no physics genius but coincidentally or by design, two key ingredients needed for the physics of this to work came together for him in Australia that summer. To understand why, we first need a quick primer on cricket balls, their speed and their bounce and something called the coefficient of restitution (COR). Don’t worry, it might sound science-y, but it really means ‘bouncebackability’ of the ball.

A cricket ball is delivered with force (generated by the bowler’s run up, his arm movement and wrist action) on to the pitch (i.e. the playing surface) and then it bounces on its way to the batsman. How high it bounces and how fast it goes depends on its COR which is basically the ratio of the velocity at which the ball is hurled on to the ground (let’s call it vg) and the velocity at which bounces off the pitch (let’s call that vp)

[For you formula nuts, that translates to COR = vp /vg]

The surface plays an important part in what the COR is like. Higher the COR (i.e. closer that ratio is to ‘1’) the more the ball will bounce up; the lower the COR, the less it will bounce. In 2011 at the International conference of mechanical engineering research, Adil Haron and K A Ismail presented a paper titled “Coefficient of Restitution of Sports Balls: A normal drop test” where they detailed results of a vertical drop test they conducted on two different surfaces – wood and steel – with four types of sports balls – golf, table tennis, hockey and cricket. The golf ball showed consistently high COR (bounced a lot and with almost the same velocity that it was dropped at; the drop height varied from 1.2m to 1.8m) regardless of surface, though as expected it bounced back up less and slower on wood than it did on steel. Its COR was about 0.8. In similar experiments, the COR of a tennis ball was found to be 0.75. Cricket ball’s COR? On the steel surface around 0.6 and on wood around 0.35. On a cricket pitch, a reasonable assumption is that the COR would be around 0.5. So, the only thing you need to remember right now is that the ball will leave the pitch at about half the speed it was delivered at.

The second piece of this puzzle is the delivery speed. At the page on the University of Sydney website called ‘The Physics Of Cricket’ they mention that if we drop a cricket ball out of a “helicopter hovering 300m above the ground it will accelerate up to 123km/hr in about 5 seconds falling through about 100m” (the acceleration is due to gravity – the force, not the Sandra Bullock movie). It will fall through the rest of the 200m without accelerating any further because the drag force of the air that pushes the ball up balances gravity which is pulling it down, thus hitting the ground at 123km/hr or the approximate speed of a Bhuvaneshwar Kumar delivery or a Wahab Riaz delivery circa 2008. Now unless you are Mohammed Irfan delivering the ball while stacked on top of Ishant Sharma standing on a step ladder that is on an elevated platform on the Qutub Minar, it is impossible to ‘vertically’ drop the ball on to a cricket pitch.

Thus it is delivered at an angle in between being perpendicular to the pitch (90 degrees) and parallel (horizontal) to the pitch, so rather than have a vertical or drop velocity it will have an angular velocity (which is a mix of the ball’s horizontal velocity component and vertical velocity component). The angle of delivery also affects the COR, and on a typical surface the COR would drop somewhat but for simplicity’s sake we will continue with the nice, semi-round number that is 0.5.

There are just a couple of final things to consider before we dive into the final calculations of how a cricket ball turns into a weapon of intimidation. First the mass of the cricket ball. A cricket ball, if you recall an infamous sledge from Greg Thomas of Glamorgan to Viv Richards after he had played and missed at a couple of his deliveries, “is red, round and weighs about five and a half ounces, in case you are wondering”1 That’s about 160 grams (an ounce is 29 grams approx). Lastly, there is air resistance that creates drag force on the ball when delivered horizontally or at an angle. At usual bowling angles, the ball slows down by about 10-12% on delivery, i.e. the speed with which it hits the pitch is that much slower as compared to the speed at which it leaves the bowler’s hand.

And now for our finale, let’s welcome into the studio, the great Seventeenth Century cricket pundit and all round scientist, Sir Isaac Vivian Richards Newton. Newton’s second law of motion was about how much force a body would have when in motion based on its mass and its acceleration.

[Hi formula nuts, you surely remember the formula Force = mass X acceleration]

That force plays an important part in the intimidation of batsman, but more on that in just a bit. Here’s the thing – the bowler delivers the ball with a certain acceleration (depending on his action and strength – think Micthell Johnson vs Stuart Binny – and the higher the acceleration the more would be the force (the mass being constant). So to strike fear in the hearts of the batsmen, the bowler needs to be able to apply a fairly large acceleration in a short amount of time; maybe impart enough speed to beat Stuart and his dad’s delivery speeds combined.

In 1932-33, Jardine consciously or unconsciously solved this part of the problem by scouting Harold Larwood to be his main man to implement the Leg Theory. Larwood bowled at speeds (i.e. the speed at which the ball left his hand) of almost 100 mph, much faster than almost all bowlers, so could whip in that extra bit of acceleration needed as per Newton’s second law’s equation.

But once released, remember the ball hits the pitch and loses velocity, partly due to the air resistance and partly due to the COR. Nevile Cardus, one of the greatest cricket writers to have ever lived, observed that Jardine may have succeeded because he got an assist from the COR of the pitches in Australia that summer. He wrote:

“For years and years, the Australian turf in good weather has been all against the rising fast ball…Even MacDonald could not bump the ball breast high is Australia…(but) Australian wickets today (i.e. at the time of that series) are not what they were: different soil is used in preparing them. This enables the…fast bowler to “lift” more than formerly.”

That ‘lift’ was because of a higher COR on the new surfaces – think of it as shifting from wood to steel in that vertical drop test. Incidentally in that paper the authors mention in the introduction that ball-surface interaction can have a great “effect on the style of play adopted by players” and even affect “the outcome of a match”. Or, as was in the case in 1933, the outcome of the Ashes.

So, finally this brings us to the Force. (The Newtonian variety, not the George Lucas variety.) Once the cricket ball has been delivered at a speed close to 160 kmph (100 mph) it will lose about 40% of its speed thanks to our friends, the COR and air resistance, but still reach the batsman in less than half a second. So, when a Shane Warne raves on air about Mitchell Johnson getting a ball past a batsman at 90 miles an hour, he is plain wrong, it is more like 60 miles an hour; still fast enough and deadly though, as we will soon find out.

A tall bowler will deliver at an angle close to about 60 degrees and the delivery will pitch and thanks to the jiggery-pokery of angular velocity and momentum, leave the pitch at a slightly lower angle (what they call ‘skiddish bounce’ in the comm. Box or studio analysis) but have enough distance to travel so that the arc takes it into the rib cage or the head of the batsman. That’s why the bowler has to bowl ‘short’, that is closer to his end of the pitch than the batsman’s. The vertical speed a cricket ball gets when dropped from about a 2m height is about 6.3 meters/second and after bouncing it becomes about 3.6 meters/second accounting for the slowdown because of COR. A bowler will bowl it also at similar speeds. Even with a COR of 0.5 and air resistance, our cricket ball will gather a lot of momentum (mass X velocity) as it leaves the pitch and heads towards the batsman. At the other end the ball will either come into contact with the bat, zip through to the keeper or hit the batsman if he is in the way or too late in getting out of the way.

The moment it hits something, there will be a ‘transfer of momentum’ (momentum of the colliding body i.e. the ball will transfer onto the body it collides with, say, the batsman) and the force with which it hits will depend on the change in velocity i.e. the acceleration of the ball. Usually when it hits a dead bat or the body of the batsman, for all purposes practical, the ball comes to a complete halt. That is pretty rapid reverse acceleration; think of it as what happens a car going from 60 to 0 in 3 seconds but only in case of the ball it is 8,000 to 10,000 times faster because all of it happens in the fraction of a second, about 0.001 to be precise.

That exerts a force of 8000 Newtons (N) [basic calculation of force = mass X acceleration], enough to lift a small car off the ground. Even at the reduced speed, that’s a lot of concentrated force. Which is why it is so dangerous to get hit by the ball2 – Bert Oldfield’s skull suffered a fracture when he was hit by a Larwood delivery, Chris Rogers suffered a bad blow to the back of his head during the recent Ashes Test match at Lord’s from a Jimmy Anderson delivery, and we all know the tragedy that befell Philip Hughes.

While the laws of physics are universally constant, as a tennis player, Devashish Joshi, who is on the Caltech team that competes in the College tennis circuit in the US and has members who are incredibly smart with rattling off physics equations and quick calculations, put it “I never think about science when playing.” That’s because out there in the middle, there is too little time to do all the calculations. Indeed, during the Bodyline series, Jardine’s tactics hit upon a fortuitous mix of the right physics in the right conditions and became important in winning the Ashes back, but it’s preposterous to think that he methodically put the pieces together with a copy of Principia Mathematica in his hand.

  1. Viv, as usual, had the last laugh by hammering Thomas’s next delivery out of the ground and replying “Greg, you know what it looks like, now go and find it.”
  2. In fact, the force is dangerous even at way more reduced speeds. I was casually bowling in the nets once to a friend of mine and got one delivery to rear up from a good length and it hit him on the ribs. I am barely 100 pounds and hardly generate any express pace but the next day I found out, my friend had suffered a fractured rib!

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