The one-day international has changed to such an extent that it is almost unrecognisable from the version that was first introduced to cricket audiences on January 5, 1971. In the early years of the format, a run-rate of four an over was considered a challenging one, with the batsmen approaching the game rather conservatively, keeping wickets in hand and going after quick runs only in the last few overs. In the 1975 World Cup, for instance, the average run-rate in the entire tournament was 3.91 runs per over; in the next edition, in 1979, it dropped to 3.54. Compare that with the run-rate in the most recent edition of the World Cup, when the overall tournament scoring rate exceeded five for the first time, and it's obvious that the way the ODI is played has changed hugely over 35 years.

With the scoring patterns undergoing such significant changes, any straight comparisons of numbers across eras becomes almost meaningless, simply because the benchmarks have changed so much: what used to be a par total in the 1980s is well below average today. It's true that batting averages have gone up in Test cricket as well, but compare the average in the 1960s (30.81) with that in the 2000s (32.02), and the difference is only 1.21 runs, which, as a percentage of the 1960s average, is an increase of 4%. In ODIs, on the other hand, the average strike rate in the 1970s was 60.39; in the 2000s, it went up to 75.06, an increase of 24%. (The average went up from 24.52 to 27.85 too. For more big-picture numbers on how the ODI has changed over the years, check out Anantha Narayanan's It Figures blog here.)

These differences are key when comparing batsmen and bowlers across eras. So here's a look at the ODI stats of batsmen across different time periods, but adjusted to account for the par scores and scoring rates during the periods in which they played.

No discussion on great ODI batsmen can begin with any name other than Viv Richards, so let's start with him. His stats are impressive enough as they are, but they become even better when put into perspective by comparing with the par numbers during his playing days. Richards' ODI career spanned 16 years, from 1975 to 1991, and he finished with a career average of 47 at a strike rate of 90.2 runs per 100 balls. But during the period in which he played one-day internationals (from his first game to the last), the batting average in ODIs for the top seven batsmen was 29.38, while the average strike rate was a mere 65.96. Multiplying the two factors (average and runs per ball) for Richards and for the average during his period, it turns out that the batting index for Richards (the product of average and runs per ball, which is 42.39 for him) is 2.19 times the average during his period. That, in a nutshell, was what made him such a great batsman - unarguably greater than anyone else who has played this format. Sample this stat to understand how destructive he was: of the 62 times when he faced 50 or more deliveries in an innings, on 25 occasions his strike rate was more than 90, and 19 times he scored at a run a ball or more.

Richards' numbers clearly stand out, but there were a few other top-notch performers too, in an era when the format was still relatively new. Dean Jones averaged nearly 45, at a strike rate of more than 72; his batting index was 1.64 times the overall batting index during the period when he played. Gordon Greenidge, Allan Lamb and Javed Miandad all have pretty good numbers too, though Greenidge's strike rate might come as a bit of a surprise to those who remember him as a swashbuckling opener with an ultra-powerful square-cut: he managed only 65 runs per 100 balls. Lamb had a higher batting index, but he also played in a slightly later era than Greenidge, when batsmen were beginning to understand better the demands of one-day cricket. Allan Border remains among the great Test batsmen of all time, but his ODI stats pale in comparison to some of the other top players in his era.

# For top 7 batsmen only
By the time the next generation of cricketers arrived, the tempo of one-day internationals had clearly moved up a notch. A look at the table below confirms that: the par strike rate for players who played in the 1990s and early 2000s moved up from about 65-66 in the earlier era to beyond 70. Thus the batting index for this generation of batsmen moved up from around 19 to around 22, which clearly shows that the benchmark to judge batting performances had moved up.

In terms of stats, the batsman who stood out in that era was Michael Bevan. Admittedly, his average is boosted considerably by his unusually high number of not-outs: out of 196 innings that he played, he was unbeaten 67 times, which is a whopping 34%. Assume a not-out percentage of 15, and his average comes down to around 41.5, which in turn brings his batting index down to around 31, and the ratio to around 1.40. However, since averages have been taken for all players, it's only fair that Bevan gets the same treatment. It's undeniable, though, that his not-outs skew his numbers more than they do for the others.

There were several other top-class ODI performers too during the late 1990s and early 2000s, in a era which was marked by many high-quality left-handers: apart from Bevan, there were Brian Lara, Saeed Anwar, Sourav Ganguly and Gary Kirsten who all finished with exceptional ODI records. The right-handers weren't left behind though, and stood out for their grace and elegance, as much as the sheer number of runs they scored.

One exception has been made in the table below, for the sake of greater accuracy. Ganguly played 311 ODIs in all, but he played his first on January 11, 1992, and his second on May 22, 1996, more than four years after his first. His ODI career was thus made up almost entirely of matches played after May 21, 1996, which is why the overall average and strike rate for him consist of matches played after that date. (Considering the matches between 1992 and 1996 would have given him an unfair advantage, since it would have included a period when the par scores and scoring rates would have been relatively lower.)

* Excludes his first match, since there was a four-year gap between his first game and his next one.
# For top 7 batsmen only

And then come the current era of cricketers, who have played their ODIs in an age when the speed of scoring has become even more frenetic. The list below consists of batsmen who have mostly played their ODIs in the 2000s. The overall averages in their era hasn't changed much from the previous table, but the strike rates have increased considerably, from the 70-72 range to the 75-78 range. For example, during the period in which MS Dhoni has played - from December 23, 2004 onwards - the average strike rate for all top-order batsmen is 77.92. During the period when Richards played ODIS, the average strike rate was 65.96, which means the strike rate in the current era is 18% higher.

Dhoni's stats, though, stand out even when compared to batsmen of time. Like Bevan's numbers, his average is also propped up by the number of not-outs (26.58%, compared to Bevan's 34.18%), but Dhoni's strike rate is considerably above average, unlike Bevan's.

And then there's perhaps the most complete batsman of all time. Sachin Tendulkar has played more ODIs than anyone else, over a period straddling 22 years and still counting. The game has changed considerably during this period, as is obvious from all the numbers in this piece, and Tendulkar has handled the changes with aplomb. Unlike a Rahul Dravid, whose game is based on defence, Tendulkar's batting is based on aggression and strokeplay, which suits the tempo of ODIs perfectly. The average run-rate during Tendulkar's span of years is 73.78, which is about four runs fewer than the corresponding number during Dhoni's timespan, which is a good indicator of how the format has evolved.

Like for Sourav Ganguly, the numbers for Matthew Hayden have also been tweaked slightly to account for the fact that there was almost a six-year gap between his first 13 ODIs - in 1993-94 - and his remaining 148. Between May 1994 and January 2000, he didn't play a single ODI, because of which all the stats till the start of the second phase of his career have been excluded in the table below.

Hayden's among five batsmen in the table below with a ratio greater than 1.50 - apart from Dhoni and Tendulkar, Virender Sehwag and Adam Gilchrist make the cut more because of their exceptional strike rates than their averages.

* Excludes his first 13 ODIs, since there was almost a six-year gap in his career after that.
# For top 7 batsmen only

And finally, here's the list of batsmen with the top ratios from across eras. Even if Richards' stats are compared with the top-order numbers during Dhoni's era, he still comes up with a ratio of 1.71, which indicates how far ahead of his time he was as an ODI batsman.

The formula of multiplying average with strike rate is an intuitive one, given that both runs scored and the rate of scoring them are important in ODIs. If, however, the scoring rate is seen as slightly more important, then that can be given a slightly higher weightage. When the value of the strike rate is raised to the power of 1.1 (which gives it a 1.1 times importance compared to the average), Richards' ratio moves up from 2.19 to 2.26, while Bevan's moves up only from 1.76 to 1.77. Sehwag goes past Hayden, while Lamb inches closer to Greenidge. The top ten then looks like this: Richards (2.26), Dhoni (1.82), Bevan (1.77), Tendulkar (1.73), Jones (1.65), Sehwag (1.60), Hayden (1.57), Gilchrist (1.55), Greenidge (1.51) and Lamb (1.50). Ten top-class names, but the leader of the pack is still far away from the rest.