The second-most important man in the side
It isn't odd that a world charmed by aggressive batsmen, daunting pacers and incisive spinners often looks through the men crouching behind the stumps, playing singular roles for their teams. A wicketkeeper is usually the most under-appreciated of the playing XI, constantly called upon to make vital contributions as a matter of routine. While a brilliant piece of fielding is usually praised when it occurs in the outfield, it simply is expected behind the wickets.
Still, wicketkeepers are called the backbone of the fielding unit and are in the thick of the action through a game. The stronger the backbone, the tougher the team appears on the field. The keeper leads the team in setting the tone for energy levels and body language. Since he's closest to the batsman, his job is to convey the team's mood to the opponent, and of course to intimidate him.
While it may be the most gruelling job on the cricket field, wicketkeeping is a thankless job. You could be at your best behind the stumps the whole day, but the big gloves will take half the credit, and if, god forbid, you drop a catch, you can almost see your world coming down. A keeper's span of concentration - the amount of time he needs to stay in the present - has to be longer than that for other players. It starts with the bowler's run-up (when the keeper looks for cues with regards to the shine, or for any other indication that might help him move better) and ends when the ball is dead. To this mental effort, add 540 squats, 90 trots of about 50 metres each, and about 200 short sprints every day.
Wicketkeepers are born, not made, they say. The craft chooses its disciple, not the other way around. Good wicketkeepers are blessed with great (read soft) hands, sharp reflexes and the right temperament.
Though it isn't a rule of thumb, and there have been exceptions, good wicketkeepers are also not very tall. Since a shorter person's centre of gravity is lower, it's easier for him to go down, and also to stay low on every ball, without too much effort. Taller guys, like Adam Gilchrist, have to remind themselves to stay low all the time.
In recent times wicketkeeping has ceased to be a specialised job - the need of the hour being wicketkeeper-batsmen. While this may add depth to batting line-ups, it may, unless monitored closely, irreversibly alter the art of keeping - the one that requires the keeper to tweak his responses to different kinds of bowlers and balls bowled.
Keeping to spinners
If wicketkeeping wasn't already tough, standing up to the stumps requires special skills. The ideal stance of a wicketkeeper is one that gives him a full, uninterrupted view of the bowler. His inside foot (the one closer to the stumps) is about five centimetres outside the line of off stump and about two feet, or an arm's distance, behind. How far back he is from the stumps depends on the height of the player. The smaller the keeper, the closer he'll need to be to the stumps.
While standing back to a medium-pacer, he can remain in a half-squat position, but he has no choice but to crouch fully while standing up to the wicket. The reason for staying crouched is to delay getting up for as long as possible, for it's easier to move upwards than down.
The keeper must start rising only after the ball has pitched, and must then move with the bounce. If he gets up earlier, he'll invariably find himself in an awkward position, especially on low subcontinental wickets - a problem faced even by the best in the business, like Ian Healy or Mark Boucher in India and Sri Lanka. India's Nayan Mongia was as good as it gets while standing up to the spinners. He'd not only stay low for the longest possible time but also rise with the ball beautifully, even on India's uneven pitches, even while keeping to the pace of Anil Kumble.
It's very important to have the gloves fully unfurled while taking the ball. Snatching at the ball is a no-no. "Receiving" is the operative word. While the palm closer to the stumps should be in line with the ball, the outer palm must cover the possibility of an outside edge. Since wicketkeepers are taught to keep their hands this way, it's unfair to be harsh when they miss inside edges, especially against spinners, because of the lack of time to rearrange the hands.
The head should be in line with the ball as you move sideways to collect the ball. Previously wicketkeepers used to be told to make an arc with the hands while moving sideways; this is now discouraged since it takes them away from the stumps. Now the advice is to move in a straight line while keeping the inside leg as close to the stumps as possible in order to get back to the wicket when needed.
For a keeper, reading the bowler is as important as it is for a batsman. It gives him clues regarding the direction of the ball, and helps him decide which way to move. For example, there is no need to move down leg side for a doosra pitched around middle stump, or to stay on the off side for a googly.
Keeping to fast bowlers
While standing back is slightly easier than standing up, when standing back the wicketkeeper is responsible for his team-mates at slip. He's the one who decides the distance from the stumps - which should ideally be the spot at which he receives a ball pitching on good length at about waist height. If the ball gets to him higher or lower, it means he's not in the correct position. And since the fielders at slip use the keeper as an indicator for bounce and pace, if he's not in the correct position, they won't be either.
The keeper's position should be such that he gets a full, uninterrupted view of the bowler, which means he has to place himself further outside the off stump for bowlers coming around the stumps. In such instances you need to be a bit lenient if a keeper misses one down the leg side, for he has to cover a lot of ground to gather the misdirected ball.
It isn't mandatory to crouch fully but most keepers prefer to do so. There are some exceptions, like Alec Stewart, who liked to stay in a half-squat. But keeping the knees flexed, with your weight on the balls of the feet, is mandatory, and you should be able to move sideways in a straight line. The idea is to take the ball beside the inside hip and cover the outside edges.
Wicketkeepers are also advised to "give" while receiving the ball, which means taking the arms back, using them as shock absorbers, while taking the ball. Though it's the right thing to do, it doesn't work in England, where the ball tends to swing a fair bit after passing the batsman. Gilchrist found that out in the 2005 Ashes and was clearly flustered in the first half of the series. In England you need to gather the ball in front of the body, using the body as a second line of defence.
A wicketkeeper must also go for every catch that's not likely to reach first slip on the full. It's better to get a hand to the ball and drop it than to not attempt to catch at all.
Keeping to the batsman
It's also the wicketkeeper's job to get under the batsman's skin, as mentioned before. I'm not promoting sledging but a bit of banter is harmless. Trust me, when someone stands that close to you - with the best view of play - and repeats things about your technique with confidence, you tend to give it a thought. And that fleeting thought might just be enough to force a false shot. I've been tempted to play a few myself, and have seen many batsmen fall for wicketkeepers' utterances. Parthiv Patel coerced Yasir Hameed into playing ahead of himself a few times on India's tour to Pakistan in 2003-04. Kumar Sangakkara doesn't fail to remind batsmen of their shortcomings either.
Since the wicketkeeper has the best seat in the box to judge the movement, pitch, a batsman's strengths and weaknesses, a bowler's mistakes and so on, he must think and act like a leader. He is a constant source of information for the captain and the bowlers.
A smart keeper brings immense value to the side: Stewart stumping Brian Lara with a smart piece of work and Brendon McCullum moving down the leg side to pre-empt Rahul Dravid's paddle sweep to dismiss him are two examples off the top of my head. There are many such instances where keepers have played a pivotal role to change the course of a game.
A good wicketkeeper also makes the team look a better fielding unit. He may run up to the stumps urging the players to throw at him, even when the batsmen are not attempting a run; he might run up to collect a bad throw on the full or collect a poor throw cleanly. He possesses the power to boost the spirits of the team and keep the players on their toes.
The keeper is the second-most important man in the side after the captain. One can almost discern the mood of the team just by looking at him.