Black soil means slow turn
The pitch at Chepauk for this game is made of black soil and therefore it should be expected to get slower as the match progresses. The square at Chepauk has two different kinds of pitches - a couple with red soil and a few with black soil. The former is used whenever a rank turner is the requirement (mostly in Ranji games) and the latter for a typical Indian surface that turns but not viciously. The toss is important but not as important as it was at Wankhede - where England managed to squander that advantage.
Importance of the full ball
The new SG ball rarely swings and there's little lateral movement off the pitch in India. The only thing a fast bowler plays with is the marginal change of lines and length, and the early skepticism of openers. In the sixth over, Ishant Sharma bowled a full, wide ball luring Keaton Jennings into a big booming drive. Openers are so focused on balls pitching in the good-length area that, at times, they are caught unawares by the full ball. In any case, Jennings' weight is on the back foot in the initial stages of his innings and is therefore always a little late on his shots.
Root starts where he left off in Mumbai
Batting is a lot about the mind space that you're in and Joe Root has shown how it dictates your response. Root wasn't a happy sweeper in the early part of this Test series, definitely not in the early part of the innings but it changed in the second innings of the fourth Test. The pitch at Wankhede forced Root to sweep right from the beginning, for that was the only way to survive on a wilting pitch. In Chepauk, he picked up where left off in Mumbai, sweeping Ravindra Jadeja and Amit Mishra fairly early in his innings. It must be said that the first-day pitch at Chepauk isn't half as alarming, although, in the end, Root was dismissed sweeping at Jadeja.
Ashwin's drift and dip
The first ball of the 27th over, bowled by Ravichandran Ashwin, drifted away in the air and went straight on with the arm, to which Root defended on the front foot. The following ball drifted in to which Root stepped out, only to see it dipping a foot shorter. These two deliveries showcased the deception Ashwin creates in the air.
Tough call
The idea of staying with the umpire's call on DRS is to discourage players from marginal reviews and to maintain the sanctity of the on-field umpire. To an extent, it's also an acknowledgment of technology not being 100% accurate. While this does make sense, one wonders why the team should be penalised for it. Mishra appealed for a leg-before against Moeen Ali and, while the ball hit the pads in front of the wicket, Hawk-Eye's projection showed that it would have just clipped leg stump instead of hitting it fully. Now, that can't be considered a bad review and therefore it is a little unfair to penalise India for it, as losing a review might mean an umpiring howler later in the innings going uncorrected.
Bairstow's driving lesson
Jonny Bairstow played an English shot on an Indian pitch. He tried to drive one on the up and hit it straight to the fielder placed for the catch in the covers. If you want to play along the ground off the front foot, you must get to the pitch of the ball, because every now and then it will either stop or turn more than expected. Moeen played in an almost identical manner but fortunately none of his shots went close to the India fielders.
(Lack of) bouncers to Moeen
Ishant dimissed Moeen with a bouncer at Lord's in 2014. Mohammed Shami dismissed Moeen with a bouncer in Mohali two weeks ago. Considering these facts you are almost sure that there will be bouncers the moment he walks out to bat. Therefore it was surprising to see so few bowled to him on the first day of the Chennai Test.