3 - Instances of R Ashwin scoring a century and taking a five-for in a Test. Before the ongoing Chennai Test, he had achieved this twice against West Indies, in Mumbai in 2011, and in North Sound in 2016. India won the Test in 2016 by an innings and 92 runs, while the Mumbai game ended in a memorable draw with the scores level - India finished on 242 for 9, chasing 243 for victory.
1 - Player who have achieved this double of a century and a five-for in a Test more often than Ashwin: Ian Botham did it five times in his 102-Test career - twice each in England and New Zealand, and once in India. Four allrounders have achieved this feat two times - Garry Sobers, Mushtaq Mohammad, Jacques Kallis, and Shakib Al Hasan.
3 - Indians who have achieved this double in a Test. Vinoo Mankad scored 184 and 72, and took 5 for 196 in England's first innings at Lord's in 1952, while Polly Umrigar made 172 not out and 56, and took 5 for 107 against West Indies in Port-of-Spain in 1962. Both those efforts came in defeats. Among the 33 instances of players achieving this feat, the batting aggregates for Mankad (256) and Umrigar (228) are first and third in the list.
2016 - The last time a player achieved the feat, before Ashwin in the ongoing Chennai Test: Roston Chase took 5 for 147, and scored an unbeaten 137 in the second innings, against India in Kingston in 2016. In the previous Test, Ashwin had achieved this double in North Sound, scoring 113 and taking 7 for 83.
33 - Total instances of an allrounder achieving this double in a Test. England lead the way with six such contributions - thanks mainly to Botham - while India and West Indies are next with five instances each. South Africa, Australia and Pakistan follow with four such occurrences for each team. Bangladesh feature three times, while New Zealand and Zimbabwe feature once each.
3 - Instances of players scoring a century and taking 10 wickets in a Test match: only Botham, Imran Khan and Shakib have achieved this feat. Ashwin will join the trio if he takes five wickets in England's second innings.
3 - Test centuries for Ashwin when batting at No. 8. Only one batsman - Daniel Vettori - has scored more hundreds when batting at No. 8 or lower: he has four at No. 8, and one at No. 9.
39.16 - Ashwin's batting average in Tests against England. The only team against whom he has a better average is West Indies (average of 50.18 from 11 Tests). These are the only teams against whom his batting average exceeds 25.

S Rajesh is stats editor of ESPNcricinfo. @rajeshstats