Prior and other prolific keepers

One of the most memorable passages of play during the first Test between England and Pakistan at Trent Bridge was during the home team's second innings. England had a more-than-handy first-innings lead, but at 72 for 5 and with Pakistan's fast bowlers threatening a wicket almost every over, it seemed the visitors might have given themselves an outside chance. Less than three hours later, though, their chances had been completely snuffed out by a splendid hundred from Matt Prior. His 102 came off just 136 balls, and so deflated Pakistan that the match was effectively over. Given Pakistan's batting incompetence, England would most likely have won even with a much smaller contribution from Prior, but that's a remark that can only be made in hindsight; at the time, Prior's knock came at a tense moment of the match, and it turned it decisively in England's favour.

Contrast that performance with Kamran Akmal's - he missed crucial chances and scored ducks in both innings - and you realise the importance of a wicketkeeper-batsman in the side. Prior's presence has been one of the key factors in England's strong performances over the last year and more: over the last three seasons his wicketkeeping has steadily improved, while his batting has hugely boosted England's lower-order display.

Prior began his Test career with a century, and subsequent events have proved that knock wasn't a flash in the pan. In 32 Tests, he averages more than 42, with 17 scores of 50-plus in 51 innings. In the 11 series he has played in since his debut, Prior has scored at least a half-century in all except one. The exception was the three-Test home series against India in 2007, when he had a highest score of 42 in six innings. In nine series since then, he has managed at least one 50-plus score in each.

A look at the team-wise batting averages of wicketkeepers shows the impact that Prior has made. Only India, thanks to MS Dhoni, have a higher average than England's 37.67. England's average has gone below India's due to the relative lack of runs from Tim Ambrose (447 runs in 16 innings) and Chris Read (six runs in two innings).

A comparison with the numbers from the seven previous years further illustrates the difference Prior has made. In the period between 2000 and 2006, Alec Stewart and Geraint Jones did the duties behind the stumps for England, and while Stewart was adequate - he averaged more than 36 from 40 Tests - Jones was clearly below par, averaging less than 24 in 34 matches. That ensured the combined average for England slipped below 30, a mark four teams topped.

Australia's decline in the post-Adam Gilchrist era is evident as well, with their average slipping from 47.55 - entirely due to Gilchrist - to less than 37. Dhoni's influence on the Indian team has been a significant one too, with the average for Indian wicketkeepers rising significantly over the last three-and-a-half years.

The story isn't such a happy one for West Indies, though. When Denesh Ramdin came into international cricket, he was roundly tipped as one of the future stars for the region, with his glovework and his batting coming in for plenty of praise. In the last few years, though, his form in both areas has dipped, and the clamours for a replacement are growing louder. In the 15 Tests he played before 2007, Ramdin averaged more than 26; in 27 Tests since the beginning of 2007, his average has dropped to 21.

The averages of wicketkeeper-batsmen since 2007 clearly show the pecking order, batting-wise at least - Dhoni and Prior are the only ones with averages of more than 40, five others are grouped between 34 and 39, and two are in the sub-30 category, though Bangladesh's Mushfiqur Rahim is well clear of Ramdin.

In fact, Prior is one of only six wicketkeepers of all time to score more than 1500 runs at an average of more than 40. Andy Flower leads the list with a phenomenal average of almost 54, with Gilchrist coming in next at 47.60, but Prior averages more than Kumar Sangakkara in the matches in which the Sri Lankan kept wicket. Sangakkara's overall Test average is more than 56, but in the 48 Tests in which he kept wicket, his average dropped to 40.48.

Among England's wicketkeepers, Prior sits pretty in second place, next only to the prolific Les Ames, who scored eight centuries in 44 Tests. Stewart, Alan Knott and Jack Russell had several memorable moments with the bat, but they all finished with sub-35 averages.