A season of Turn and Bounce in IPL

A quick flashback to the first wicket of IPL 2019 - Harbhajan Singh bowling the fourth over to Virat Kohli. He pitched the third ball short. Following his muscle memory, the RCB captain rocked on the back foot, attempting a pull.

Though it was pitched short, Harbhajan was able to spin the ball into Kohli’s body. As a result, though Kohli got a decent connection, all he could do was find Ravindra Jadeja at deep mid-wicket.

The next wicket: Moeen Ali tried to play Harbhajan off the back foot in the bowler’s next over, but committed too early to the shot. He toe-edged the ball back to the bowler. AB de Villiers fell next, victim, as Kohli was, to the inability to force against the spin and getting caught at deep mid-wicket.

Two points are worth noting here: One, that CSK decided to use an off spinner as early as the second over of the powerplay and two, that the Chennai track was overly conducive to spin, to such an extent that though CSK won the match, its captain MS Dhoni was openly critical of the quality of the pitch in the post match interview. RCB, unused to batting on such tracks, was bowled out for a paltry 70. In reply, CSK took 18 overs to get past the target. The much-anticipated 12th season of IPL had an anti-climatic start, thanks to one of the slowest tracks in the history of the tournament.

Things improved there on, with the next three matches witnessing at least 170 runs on the board in each innings -- but the unprecedented role of spinners foreshadowed in that tournament opener was there to stay.

When T20 was introduced, analysts wrote the obituary of spin, arguing that a format designed for big hitting would be the death of bowlers whose slowness made it easier for the big-hitters to find the time for their shots. Spinners have since proved those analysts wrong, and the recently concluded season have established their role as potent, match-winning weapons in the shortest format.

Numbers tell part of the story of the resurgence of the spinner. Thus:

The 2019 edition marks the first time spinners bowling more than 40% of deliveries in an innings - almost twice the number they bowled in the inaugural 2008 edition. This reflected also in the fact that spinners accounted for 41.2% of all dismissals - another record. CSK, the eventual runners-up, saw their spinners scalp 62 wickets in the season while pace accounted 44.

The application of spin increased by 8.7% in Hyderabad this year as compared to the previous three years combined (2016-18). In Delhi, the number augmented by 12.1%. Only in Kolkata, the figure reduced by an appreciable margin of 4.2% because of a rejuvenated track at the Eden Gardens. In rest of the grounds, the percentage of spin has remained fairly similar - moderately increasing in Bangalore and Mohali.

Remarkable as those numbers are, what was eye-catching, and could have long term repercussions, is this: Where earlier spinners hardly ever bowled in powerplays (in 2008 a mere 4.3% of the deliveries were spin), this season saw spinners bowl 25.2% of all deliveries, second only to 26.6% in 2018.

To add nuance to those numbers, most of the spinners who bowled in the powerplays in the initial years of IPL were finger-spinners such as Yusuf Pathan, Harbhajan Singh and Ravi Ashwin. This year, Chahal bowled 74 balls in the first 6 overs while Chawla bowled 132 balls during the field restrictions last year -- heralding the advent, and increasing dominance, of the wrist spinner. This is particularly remarkable because cricket dogma suggests leg spinners are easier to hit than off spinners, because wrist spin is by definition more flighted, and slower than the finger variety.

What the graph above illustrates is that alongside the spinner’s increasing influence in powerplays, they have also become a force in the mid-innings phase.

This impact is best illustrated by the fourth game of the season, Rajasthan was at a comfortable 78/0 in eight overs, in a chase of 184. KXIP captain Ravi Ashwin began his second over with a carrom ball that crashed into Ajinkya Rahane’s stumps, and conceded only five runs off the ninth over of the innings. His overall figures - 4-0-20-1 -- were enough to derail the Royals and give Punjab a comfortable 14-run win.

Another example: Shreyas Gopal ran through Bangalore’s batting, dismissing Virat Kohli, AB de Viliers and Shimron Hetmyer in his first three overs. Again, in the final, Chennai had a decent start with the scoreboard reading 57/1 in seven overs in a chase of 150, when Rahul Chahar came on to produced a spell of 4-0-14-1 that helped Mumbai get back in control and emerge as eventual winners.

There are two points worth noting here: That in the middle phase, spin played the double role of enforcing control and taking wickets, as demonstrated by the economy and strike rates.

The average economy of spinners in the middle-overs this year was 7.29 - the best across the last 6 seasons. A dot ball percentage of 34.4, and a boundary percentage of 12.38 are also ahead of any of the previous 6 seasons. To top it off, they took wickets as they never have before.

As pointed out earlier, early theory preferred the finger spinner to the wrist spinner. In fact, no leg-spinner took the field in any of the first five T20Is.

Shane Warne, the third highest wicket-taker in the 2008 IPL, and Anil Kumble, the Purple Cap winner in 2009, were harbingers of a change in attitude towards the wrist spinner -- and 2019 was the culmination of what Warne and Kumble began, with this season seeing the wrist spinner at his peak.

Chennai Super Kings, one of the most successful franchises, did not field a single leg spinner in its first five seasons. In contrast, today every franchise has invested heavily in at least one quality leg-spinner to bolster their wicket-taking options. IPL 2019 is the first season in which wrist-spinners from each franchise bowled more than 200 deliveries.

We use the middle overs here to level the playing field, because this is the phase where both types of spinners bowled the most overs. Imran Tahir, the Purple Cap winner this year with 26 wickets, picked 24 wickets of those during the middle phase - the highest number of wickets taken by any bowler during the middle overs in a season, across all seasons. To underline the wrist versus finger argument, Tahir ended up with five more than the season’s most successful off spinner, Harbhajan Singh, whose 19 wickets (2013 season) were taken in two more games than Tahir.

Trivia alert: For reasons beyond rational explanation, wrist spinners seem to work their magic most in the seventh over of an innings: In the 2019 season, leggies took 15 wickets in the seventh over - the most by them in any particular over of a game. You tell us why. 

Irony Alert: Given all of this, you would imagine that Kolkata Knight Riders, with one of the best spin attacks of the season, would have ruled. In fact, though, KKR spinners conceded 8.97 runs per over, and their strike rate of 29.7 wasn’t close to the best. Their best spinner between 2016 and 2018, Kuldeep Yadav (23 wickets at a strike-rate of 16.5) went wicketless for four games in a row. In the fifth game, Yadav conceded 27 runs in an over to Moeen Ali -- and never bowled a ball after that

With a combination of uncharacteristically slow tracks, some shrewd magicians with the ball in action and efficient use of their art by their skippers, this year’s IPL has supported the slow bowlers, particularly attacking leg-spinners, more than it has ever had.