Virat Kohli scored a record-breaking 973 runs in the 2016 IPL, the most in a season. Dwayne Bravo took 32 wickets in 2013, the most ever in a season. The absolute values of those runs and wickets are immense, but what about their actual value and impact on those matches? Did another player score fewer runs or take fewer wickets, but do so in more high-pressure and demanding situations?

Enter Smart Stats, a set of metrics developed by ESPNcricinfo, which takes into account the context of each batting and bowling performance. Context is quantified by calculating the pressure on the batsman and bowler for each ball, factoring in runs required, overs remaining, quality of batsmen at the crease and those to follow, quality of bowlers and number of overs left for each; plus the pitch/conditions, and how easy or tough it is to score runs.

Based on these factors, each run scored or conceded, and each wicket taken, is given a value, which are the Smart Runs or Smart Wickets. Also, each batting and bowling performance is given an impact value, which depends on the pressure under which they performed.

Thus, for each IPL season, there is a Smart Runs and Smart Wickets leaderboard, as also the top player of the tournament, which is based on the impact points scored per match. Here is a season-wise comparison of the smart numbers with the actual values across IPL history.

Orange cap
Out of 12 seasons so far, there have only been two seasons when the leader in terms of Smart Runs isn't also the top run-scorer of the tournament. In 2013, Michael Hussey won the orange cap with 733 runs, but as per Smart Stats Chris Gayle's 708 runs were worth 773.46 Smart Runs, while Hussey's Smart Runs were valued at 726.94.

The bigger surprise would be the smart numbers from the 2016 season. Kohli's aggregate of 973 was 125 more than David Warner's 848, but in terms of Smart Runs Warner's tally was worth 935.52 runs to Kohli's 925.24. Kohli's strike rate of 152.03 was similar to Warner's 151.42, but that does not tell the real story. In the matches Kohli played, the average scoring rate was 9.22 runs per over, while the matches involving Warner only saw a rate of 8.05. In Bengaluru, the home venue for Kohli, the average strike rate was 149.34, while in Hyderabad, Warner's home venue, the average strike rate was 121.19. Also, Kohli had much better support, with AB de Villiers and KL Rahul also making substantial scores: the other RCB batsmen scored at a strike rate of 153.91 in the season, while the other Sunrisers batsmen scored at only 120.04. In a relatively weak line-up Warner was clearly the star, and because he consistently batted under greater pressure the difference between his Smart Runs and conventional runs tally is much higher.

Purple cap
There have been five seasons when the bowler with the most conventional wickets in the tournament was not the bowler with the most Smart Wickets. The first time that happened was in the 2013 season, when Bravo got the purple cap with 32 wickets. However, in terms of Smart Wickets, Mitchell Johnson finished on top: his 24 wickets were worth 27.2 Smart Wickets, while Bravo's Smart Wicket haul was only 24.8.

That difference is because of the quality of wickets that Johnson took. Of his 24 wickets, 16 were of the top three batsmen in the opposition line-up; on 17 occasions, the batsmen were dismissed before they reached 15, while six times they fell without scoring. The batsmen who were dismissed for ducks include Tillakaratne Dilshan, Aaron Finch and Suresh Raina. On the other hand, 20 of Bravo's 32 wickets came in the death overs, when batsmen are going for quick runs and getting wickets is easier for a bowler. Some of those wickets are no doubt crucial, which is factored into the Smart Wickets calculation as it takes into account match context, but very often they don't mean as much as dismissing a top-order batsman for a low score.

Only once in the last five years has the leader in the Smart Wickets category also been the top wicket-taker in the tournament. In the last two seasons, the purple cap holder isn't the one who tops the Smart Wickets charts: in 2018, Rashid Khan (21 wickets, 26.3 Smart Wickets) topped Andrew Tye (24 wickets, 26.1 Smart Wickets), while Deepak Chahar ranked ahead of Imran Tahir last year.

Top impact player of each season
Like the bowlers' list, there are five instances when the Smart Stats player of the tournament did not coincide with the official winner. The first of these was in the second edition of the IPL, in 2009, when Adam Gilchrist was declared player of the tournament; according to smart numbers, Matthew Hayden had the highest impact per match value of 69.35 (among players who played at least 10 matches in the season). He was also the top run-scorer of the tournament with 572 runs, 77 more than Gilchrist's 495. However, the smart values only take into account the batting and bowling performances; in 2009 Gilchrist, apart from being the wicketkeeper, also led Deccan Chargers to the title. Those are contributions that cannot be measured by Smart Stats.

The following season, Sachin Tendulkar was the official player of the tournament for his tournament-topping 618 runs at a strike rate of 132.6, but according to Smart Stats, the most impactful was his Mumbai Indians team-mate Kieron Pollard. Pollard scored 273 runs (which was worth 339 Smart Runs) at an outstanding strike rate of 185.7, and also took 15 wickets at a healthy economy rate of 7.40. In fact, that is one of only eight instances in IPL history of a player scoring 250-plus runs and taking 15 or more wickets in an IPL season.

The most recent such instance was in 2016, when Kohli lost out to Chris Morris. Morris' 195 runs, scored at a strike rate of 178.9, were worth 239 Smart Runs. According to Smart stats, the most impactful match performance of the season came from him, against Gujarat Lions. He dismissed Brendon McCullum and Suresh Raina, and then, coming in at 57 for 4 in the 11th over in a chase of 173, nearly took Daredevils home with a stunning unbeaten 82 off 32 balls. They fell short by just one run.