Sri Lanka's over-reliance on Sanga and Mahela

For a while now, the batting fortunes of Sri Lanka have been linked inextricably with those of their two best batsmen, Kumar Sangakkara and Mahela Jayawardene. Not only are they the best among the current lot of batsmen in Sri Lanka - they are way ahead of competition in that regard - but they're also arguably among the best three that the island has ever produced. (Aravinda de Silva is the other name that belongs at the very top, but he didn't do his talent justice with a Test career average of 42.97. Already these two are about 2000 runs clear of their nearest competitors in terms of Test runs scored by Sri Lankan batsmen, and they're far from done yet - in fact, they're both enjoying some of their best years in international cricket.

The last six years have been outstanding ones for both. For Jayawardene, the current year has been a disappointing one despite a superb century in Galle against Australia: in eight Tests he averages 25.92, with only one century. In each of the previous five years, though, he averaged more than 50, almost touching 100 (98.20) in 2007. So far in 2011, though, he has been less than prolific, and his failures in three innings of the current series against Pakistan have been among the main reasons for Sri Lanka's problems so far.

Sangakkara has been in a rich vein of form, too, especially since he gave up wicketkeeping duties. His monumental double-hundred in Abu Dhabi allowed Sri Lanka to escape with a draw against Pakistan, and that form has carried over to the second Test as well. His last few knocks of the year have propped up his 2011 average as well, which is now almost 50 (after the first innings of the Dubai Test). Overall, in the54 Tests in which he hasn't kept wicket, Sangakkara's average is a staggering 71.91.

In fact, since the beginning of 2006, both he and Jayawardene have been among the top three in terms of Test averages (with a 3000-run cut-off). Jacques Kallis is the one batsman who squeezes in between the two, but Sangakkara's average of 67.36 is way ahead of anyone else's during this period.

Sangakkara and Jayawardene have held Sri Lanka's batting together for the last few years, and there's plenty to like about their stats. The table below, though, also shows one aspect that isn't so flattering. Both have outstanding averages at home - more than 70 since 2006 - and Sangakkara's numbers overseas have picked up as well, but the one aspect of Jayawardene's stats that has always confounded experts has been his performances outside the subcontinent. Though he possesses an excellent defensive technique and strokes all around the wicket, his average outside the subcontinent is a modest 35.98; over the last six years it has come down further, to 31.08.

Admittedly, part of the problem is also that Sri Lankan don't play that much outside the subcontinent. While India, and even Pakistan, tend to tour Australia, South Africa, England, New Zealand and West Indies reasonably regularly, Sri Lanka do so far more infrequently, and even when they do, it's often for only a two-Test series. Since January 2006, for example, India have played 27 Tests outside the subcontinent, Pakistan 24, and Sri Lanka a mere 12. The vagaries of the FTP can explain some of the discrepancy but not such a huge difference.

Even so, Jayawardene has struggled in these conditions more than a player of his class should. On the tour to England earlier in 2011, he scored 103 in six innings; he did reasonably well in Australia in 2007-08, scoring 167 in four innings, but managed only 39 in four innings on the tour to New Zealand before that. When opportunities are so scarce, these failures get magnified even more.

Sangakkara, on the other hand, had very good Tests in Australia and New Zealand, though his 2011 series in England was only salvaged somewhat by a century in his last innings. (Click here for his series-wise stats.)

Even with slightly dodgy numbers outside the subcontinent, though, Jayawardene remains way ahead of other Sri Lankan batsmen, excluding Sangakkara. In the 49 Tests in which both these batsmen have played for Sri Lanka, they've scored almost 42% of the team's top-order runs, and more than 50% of the hundreds. Together they've averaged 62.60, while the rest of the top-order has averaged less than 38.

And here are more comparisons between the Sangakkara-Jayawardene combination and the rest of the top order. Overall in these last six years, these two have outperformed the rest of the Sri Lankan top order by around 66%. In wins that figure increases to 73%, but in defeats it drops to around 34%, and outside the subcontinent to around 38%. The message is clear: Sri Lanka bank on Sangakkara and Jayawardene to massively outperform the rest of the top order. When they do by about 70%, the team does well; when the percentage of outperformance is only about 30-40%, the team continues to struggle.