The tournament of the short ball

"He is ducking but can't duck. He is pulling but can't pull. The hands move in slow motion for the pull, and the ball hits the glove to lob up to Dhoni."

That was India's first wicket of this World Cup, vividly described by Sidharth Monga on ESPNcricinfo's ball-by-ball commentary. The bowler was Mohammed Shami, the batsman was Younis Khan. The delivery, as you've no doubt gathered, was a fast, accurate bouncer. It is the type of ball that has dominated this World Cup, the most effective weapon of both aggression and defence.

There could hardly be a better portrayal of how the bouncer has played on the minds of batsmen throughout this tournament. It is a World Cup. It is one-day cricket. Runs must be scored, bowlers must be dominated. Play the shot, the batsman tells himself. The other voice in his head says, these pitches are quick, save yourself. Does he trust Dr Jekyll or Mr Hide?

It is not just the pace in the surfaces that has made the bumper so central to this campaign. At the last World Cup, five fielders were allowed outside the circle out of the Powerplays. Now it is four. At the last World Cup, only one ball was used at the start of an innings. Now it is one from each end. At the last World Cup, one bouncer per over was permitted. Now it is two.

Consider those rule changes in combination. You are a captain. You can place only four men on the boundary. You have good fast bowlers at your disposal. Where do you put the fielders? What do you ask of your bowler? The yorker has long been the staple of one-day cricket containment. Better to err too full than too short, the commentators used to say. Now a low full toss is liable to go for six.

A low full toss might go nearly anywhere. But what if you bowl short? If your bowlers are fast enough and accurate enough, it is a much easier delivery to defend. A successful shot will likely go more or less square of the wicket, an unsuccessful one behind the batsman. And if he is good enough to hook for six on these quick pitches, with balls that stay hard longer, good luck to him.

Over the past month, so many hooks have been skied you'd think Kareem Abdul-Jabbar was playing. Morne Morkel is South Africa's leading wicket-taker in this tournament; around half of his breakthroughs have come from bouncers. That is perhaps not unusual for Morkel, given his natural style of bowling. But he is far from alone.

One of the most notable features of India's bowling displays in this tournament has been their successful use of the bouncer. It is the equivalent of Australia heading to the subcontinent for a World Cup and spinning teams out. It is all the more surprising given how insipid India's attack was during the recent Tests in Australia.

But after the Tests ended, there was a clear shift in India's approach to net sessions. The fast men placed special emphasis on bowling their bouncers. The batsmen worked hard on facing them. It was like an unsaid acknowledgement that this would be an important aspect of a World Cup in Australia and New Zealand. And so it has proved.

"Nobody expects my bouncer to come so fast because it skids as well," Mohit Sharma said during this World Cup. "That's a plus for me because my bouncer catches the batsmen off guard and as a result there will either be a top edge or they will get beaten. I have been hit for fours and sixes also off my bouncers, but that's how it goes."

Mitchell Starc is the leading wicket-taker after the pool stage, with 16 victims, thanks largely to his swing. But his swing has been all the more effective because the threat of the bouncer is always there. It was notable that his first ball of the tournament was a bouncer, to Moeen Ali. So was his first ball against Scotland. From then on, it was in the minds of the batsmen.

Dale Steyn has likewise used the bouncer to good effect, and his dismissal of Ed Joyce in Canberra was a classic fast bowler's one-two. Steyn's bouncer pushed Joyce back, and his next ball was fuller and fast at 146kph. Joyce played away from his body with feet rooted to the crease, and sent an edge to first slip.

The size of the fields in Australia adds to the danger - more so than in New Zealand, for a batsman must really connect with a bouncer in order to clear the boundary. Perhaps that is less evident at Adelaide Oval, where the square boundaries are shorter, but then again that is where India used the bumper effectively against Pakistan. It is also, as Pat Cummins noted this weekend, one of the quickest wickets right now.

"Having all our games in Australia, I think the bounce is really important," Cummins said. "You can bowl two of them an over and if you execute it well you can defend it pretty well or it can be a dot ball, which, especially towards the end of an innings, can be gold, so definitely something I think we're going to continue using."

So too have Australia's quarter-final opponents, Pakistan. Wahab Riaz, Mohammad Irfan, Sohail Khan - they have all used the bouncer to good effect in this campaign. As Osman Samiuddin wrote last week, Pakistan's use of the bouncer is like when Indiana Jones resignedly takes out the gun on the guy with the sword. If their swing doesn't work, their bouncer probably will.

Field restrictions, two new balls, two bouncers per over - it has all combined to make this World Cup the tournament of the short ball. The idea of bouncers flying under the radar is about as oxymoronic as the term "tail-end batsman". Until now, though, bouncers have perhaps not been given their due in one-day international cricket. But when India start bouncing out opponents at Adelaide Oval, you know something is up.