Through much of second part of the 2010s, Test-match batting was dominated by the Fab Four, and with good reason: they all reached great heights in the period between 2014-19, averaging over 50. In fact, they all had a four or five-year period when they maintained an average of over 57 in more than 40 Tests.
Five years later, the picture looks quite different. While Kane Williamson and Joe Root have been in sparkling form - underscored most recently by Root's splendid twin-hundreds against Sri Lanka at Lord's - Smith and Kohli have struggled to replicate those golden years. In fact, Root scored as many Test hundreds at Lord's last week as Kohli has in the entire period from 2020 to 2024.
Here's a look at all the key numbers on the Fab Four which illustrate just how varied their returns have been in the last five years.
All about the averages
Let's start with the period between 2014 and 2019. The only batter who could stay with them in this period was David Warner. Smith had an incredible 24 hundreds from 56 Tests, while Williamson and Kohli both averaged fewer than three Tests per century. Root wasn't as sharp, but still averaged over 50, and there was a clear five-run gap between Root and the next-best.
Since 2020, though, plenty has changed. While Williamson and Root have maintained, or even improved upon, their high standards, Smith has come back to earth from his stratospheric levels, and Kohli has had a terrible slump: among the 24 batters who have scored at least 1600 Test runs since the start of 2020, only Zak Crawley has a lower average than Kohli's 33.59. Williamson, on the other hand, averages more than twice as much as Kohli does in this period.
All of this has adversely affected the career averages of Kohli and Smith. From a high of 55.10 after his 81st Test, against South Africa in October 2019, Kohli's average has dropped to 49.15 - he is the only one among the four to average under 50 - while Smith has fallen from a lofty 64.81 after his 67th Test in September 2019, to a still-impressive-but-much-lower 56.97 after 109 matches. None of that has affected Root, though, whose career average has been moving in the opposite direction: from 47.35 in November 2019, it has gone up by more than three points to 50.93. That's similar to the upward curve for Williamson - from 51.44 at the end of 2019, to 54.98 now.
A good indicator of form and consistency is the moving average, when the blocks used are reasonably small. The graph below plots averages for each of these four batters in overlapping eight-Test blocks (Tests 1-8, 2-9, 3-10 etc) - this would typically cover a period of a few months to a year (though with the lopsided schedules, the range could wary vastly for different players). Root's average in most recent eight Tests is 75.73, Williamson's is 73.54, Kohli's 55.15 and Smith's 37.69.
Kohli's hundreds in Ahmedabad and Port of Spain in 2023 has lifted his moving average recently, but before that there was a period of 21 consecutive plot points when his moving average was under 35; that refers to the period between October 2019 and June 2023, when he averaged 30.97 across 28 Tests, with the eight-Test low point coming in 2022-23, when he averaged 20.61 across 14 innings.
In stark contrast, in the last five years Root's moving average has not gone under 40 across more than three consecutive plot points. He averaged more than 50 across 17 successive plots, in a 24-Test period in 2020-2022 when he averaged 52.31. Similarly, in Williamson's last 20 moving averages - which includes 27 Tests, going back to August 2019 - only once has the number dipped below 50.
The comparison with team-mates
Between 2014 and 2019, each of the Fab Four towered above the other players in their teams. Warner's 50.94 was a super-impressive average, but even that was dwarfed by Smith's 72.02. With a 2500-run cut-off, the next best for New Zealand after Williamson's 61.95 was Ross Taylor at 45.39; Kohli's 58.71 was followed by Cheteshwar Pujara's 45.10, while Root's 50.82 was well clear of Alastair Cook's 42.68.
Overall in this period, all four batters averaged significantly higher than their other team-mates in the top order (Nos 1-7). Smith was in a league of his own even in this elite group, averaging 33.34 runs more than his top-order team-mates in the innings in which he batted. Williamson, Kohli and Root had impressive numbers too, averaging between 18 to 24 runs more than their top-order team-mates. In terms of rank, these differences were the top four among all batters who played at least 50 innings in this period.
Since 2020, though, that difference has nosedived for Kohli and Smith. The contrast is especially stark for Kohli - from 19.87, the gap has dropped to a mere 2.68, which essentially means he is only marginally better than the average Indian top-seven batter in this period. It's true that runs were generally hard to come by for most Indian top-order batters in this period - the average for the other batters dropped from 38.84 to 30.91, a fall of 20.4% - but the fall was far steeper for Kohli, whose average fell by almost 43%.
Similarly, the numbers for Smith have fallen dramatically too, from a lofty 72 to 45, even as the other Australian batters have more-or-less maintained their numbers. Williamson and Root, on the other hand, have improved on their 2014-19 stats, illustrating quite clearly how the Fab Four has now been split right down the middle. The ranks tell the story: Williamson and Root rank one and two, while Smith has dropped to 20, and Kohli to 26, among batters who have played at least 30 innings since 2020.
The percentage contribution to team runs tells the same story: from the highs of more than 16.5%, it has come down to under 13% for both Smith and Kohli.
The century count
The most striking aspect of the graphic below is the way Root has caught up with, and gone past, the other three batters over the last four years. At the end of 2020, Root had 10 fewer hundreds than Kohli, and nine fewer than Smith. Since then, Kohli has added only two centuries to his count, and Smith six, while Root has added a whopping 17 in these last few years.
In fact, since the start of 2021, Root has scored as many hundreds (17) as the three others put together. Williamson has been prolific in this period too with nine hundreds, but has played only 18 Tests compared to Root's 48. So, if we pair them up, Root and Williamson have scored 26 hundreds from 121 innings, while Smith and Kohli have eight from 104.
It helps, of course, that England have played many more Tests in this period - 48 since 2020, compared to 35 by India, 34 by Australia and just 25 by New Zealand. To Root's credit, he has gone ahead and fully capitalised on those opportunities.
The series toppers
Out of the 18 series that Smith played between 2014 and 2019, he was the top run-getter from either team seven times, which is one such instance every two-and-half series. Kohli achieved it five times in as many series. Since 2020, there has only been one such instance for either of them from the 22 series they have played, when Smith scored 231 runs in a three-Test home series against South Africa in 2021-22. Kohli hasn't top-scored once in 11 series in this period.
Meanwhile, Williamson and Root have gone from strength to strength with four top aggregates in 12 and 15 series. Root is likely to add a fifth in a week's time, given the mountain of runs he has scored in two Tests against Sri Lanka.
Tackling pace and spin
In the 2014-19 period, all four batters had excellent numbers against both pace and spin. In fact, apart from Root's average of 47.48 against pace, they all averaged more than 50 against both fast bowlers and spinners. The standout numbers were Smith's average against pace (82.15), Williamson's against spin (86.1) and Kohli's against spin (77.03).
Since 2020, though, Smith's average against pace has fallen to 40.41 - less than half of what it was in the earlier period - while Kohli has averaged in the mid-30s against both. Williamson, on the other hand, has averaged more than 60 against both pace and spin.
All these numbers indicate that the grouping of four is now down to two, based on stats over the last five years. Kohli's Test form has fallen away dramatically - though he has shown signs of revival with a couple of centuries last year - while Smith is no longer the run-machine he was in his pomp. Root, meanwhile, has rediscovered the form and hunger which had deserted him through the late 2010s, and Williamson has made excellent use of limited opportunities. But for Smith and Kohli, a high-profile Australia-India Test series later this year might not be a bad place for them to prove that they still belong in that elite league that they were a part of for much of the 2010s.
With inputs from Shiva Jayaraman. Graphics by TS Girish and Paul Muchmore