Why did CSK slow down?
Chennai Super Kings scored 91 off their first 10 overs, but then made only 78 off their next 10, an odd deceleration for a T20 match, especially since they did not lose too many wickets. So what happened?
After Ambati Rayudu was dismissed, Jasprit Bumrah, who had bowled just one over in the first ten, came on to bowl the 13th. MS Dhoni, who had just come in, left one alone and then played three defensive strokes, all for no runs, letting Bumrah complete a one-run over. Those four balls seemed to take the steam out of Super Kings' innings. Dhoni took his time, getting just four runs off his first ten balls. CSK scored 15 runs from overs 11 to 14 and could not make up for it in the death.
It looked like Dhoni had decided to play out Bumrah, whom Rohit had held back for the middle overs and the death. This cost Super Kings, and when they tried to take on Mitchell McClenaghan, they lost wickets and ultimately fell short of a winning total.
One reason for Dhoni's early struggle may have been that the pitch was a bit two-paced. Dhoni said after the game that it was difficult to score off the Mumbai Indians quicks as they were banging the ball in with pace and it was not coming on to the bat. The statistics seem to back Dhoni up. Over both innings, the fast bowlers conceded only 51 off 49 short and short-of-good-length balls, and even the usually fluent Evin Lewis struggled to time the ball.
Rohit moves up and wins it
Rohit Sharma, who had come in at Nos. 4 or 5 in Mumbai's four previous games, promoted himself to No. 3 against CSK. Rohit has always been a slow starter - his first-ten-ball strike rate this season was 95.74 before this game - but he can be a match-winner when set. Coming in at three allowed him to bide his time - he scored only six off his first seven balls - and by the time the crunch overs came along, he had his eye in and was able to win the match with four fours in the 19th over. Given his performance, he may even consider going back to the opening spot.
Why Thakur and not Bravo in the 19th?
Captains these days rarely save their best death bowler for the final over of a tense game. They usually give him the 19th, so he can create pressure by leaving a big target off the final six balls. But with Mumbai needing 22 off two overs, Dhoni gave the ball to Shardul Thakur rather than Dwayne Bravo, one of the most experienced death bowlers in T20 cricket. The idea may have been to leave Bravo with eight or 10 to defend off the 20th, but the problem was that Thakur came into the game as this season's most expensive bowler in overs 19 and 20 (among those who have sent down a minimum of 18 balls in this phase), with an economy rate of 14.50 across four overs. His record only grew worse, as he went for 17, leaving Mumbai only five to get from the last over.
Perhaps Dhoni was wary that the batsmen could have become used to Bravo, having faced him for three overs on the trot from one end, but given that he had only gone for 21 off those three, it made sense to bowl him before it was too late. As it happened, he didn't even bowl the final over, which went to Imran Tahir instead.
Why isn't Jadeja bowling?
Ravindra Jadeja is the seventh-highest wicket-taker among spinners in the IPL, and has an economy rate of 7.82 in all T20 cricket. But this season, he has only bowled 10 overs in seven games, completed his quota just once, and not bowled at all in two games, including the one against Mumbai.
What's going on? Well, he had a poor 2017 season with the ball, going at 9.18 an over and taking just five wickets in 12 innings. Over the past two years, Jadeja has vastly improved as a Test bowler, but it may have come at the cost of his white-ball bowling. He has lost his place in India's limited-overs sides, and Dhoni may be concerned about his lack of recent cricket in the T20 format.
Super Kings have Imran Tahir and Harbhajan Singh, who both had much stronger IPLs last season than Jadeja, as spin options, so Dhoni has not needed to get too many overs out of Jadeja. He may also be looking for the right match-ups. Against Mumbai, Evin Lewis, who strikes at 157.17 against left-arm spin, batted through the middle overs, so Dhoni may have been looking to protect Jadeja from him.
Jadeja hasn't done too much with the bat either this season, scoring only 47 in six innings while being unbeaten three times on 0, 3 and 11 - which tells you how little time he has had at the crease - but even if he continues to hardly bat or bowl, he will probably remain in Super Kings' XI given they only have one other experienced Indian batsman on the bench, M Vijay, who is an opener.