Awesome Indian batting.
Ian Chappell may or may not be right in suggesting that India can't be a long term Number One in tests because they lack quality bowling. Time will settle that. What is beyond dispute is the amazing Indian batting.
In the last 10 years India played 105 tests winning 42, losing 27 and drawing the rest. This is a win/loss ratio of 1.55. For the last 5 years these numbers (55, 22, 11, 2) are even more impressive. For comparison, in their entire history India played 437 tests winning 103 and losing 137. The win/loss ratio is 0.75. No one can deny that batting is the force behind this transformation.It is true that bowling was also crucial because we need 20 wickets to win. However, the win/loss ratio could be improved simply by losing less (even if winning at the same rate). Indeed, while the winning rate (compared to history) improved significantly in the last 10 years, it did not change in the last 5 years (in both the 10 year and 5 year period, it is exactly 0.4). So the improvement in the win/loss ratio from 1.55 to 2 was solely because India lost less.
Batting is the reason for this reduction in the number of losses. Big scores in wins loom large in memory. The batting in the current test again South Africa was beautiful and solid. Similarly in all the wins in the last few years in all countries, batting was awesome.
But a major aspect of Indian test performances lately has been the dogged batting when needed to save test matches.
Ahmedabad last year against Sri Lanka, or Napier, or Bangalore (against Aus, 2008), or Lord's 2007, or St Kitts in 2006 -- in all these cases India needed to bat close to a day or more in the 4th innings to avoid defeat. A few years ago the outcome usually was all too painful and predictable: India would collapse under the pressure and fail to survive. But in the past 4 years or so, there is a clear and pleasing pattern of resistance and determined batting for close to 100 overs (or more) to survive test matches.
This is surely one of the crucial reasons for our Number One position.