England's lower order makes the difference
England's lower-order-led recoveries from 87 for 7 in the first innings at Edgbaston and 86 for 6 in the first innings at the Ageas Bowl were crucial to their series win. India's lower order did not make a significant contribution till the last Test, when Ravindra Jadeja and Rishabh Pant found form. Over the first four Tests, India's top order actually outscored England's, but their lower order didn't quite match up despite having batted an extra innings.
While England's innings maintained and sometimes even gained momentum after the fall of the fifth wicket, India could not count on the same luxury. The importance of England's lower order is further highlighted by their ninth-wicket partnership averaging of 36.71 - a figure bettered only by their third and fifth wickets. Stuart Broad, batting at No.10, was part of three half-century stands.
Virat Kohli scored 26% of all India's runs while the rest of the top order got 49% of them. England were much less reliant on one player, with Joe Root scoring 13% of the runs and the lower order contributed 36%.
Moeen outbowls Ashwin
R Ashwin had an excellent start to the series, taking 7 for 121 at Edgbaston. But, on a turning pitch in Southampton, he managed just three wickets, while England's offspinner, Moeen Ali, took nine. Though Moeen played just two Tests in the series, his impact was greater than Ashwin's.
Ashwin may not have been 100% fit at the Ageas Bowl following a hip injury sustained at Trent Bridge. He also had the disadvantage of having to bowl 246 of his 311 balls to left-handers. Ashwin usually likes bowling to them, but in the fourth Test, all the rough was outside the right-hander's off stump, where India's pacers had left footmarks from bowling round the wicket.
Moeen bowled 240 of his 252 balls to right-handers. But Ashwin was ineffective against them too, possibly because he didn't pitch it wide enough. Moeen pitched more than half of his deliveries wide outside off stump, where the rough was, and got the ball to turn dramatically from there.
India's pacers get close to England's
It is nigh impossible to bowl better than James Anderson, Stuart Broad and Co. in English conditions, but India's seamers made the Test series interesting by getting close. While Anderson was a notch above everyone else, Ishant Sharma, Jasprit Bumrah and Hardik Pandya had averages on par with the rest of England's quicks. Mohammad Shami's wickets cost him more, but he was a bit unlucky through the tour.
India's seamers did their best to bowl fuller to get the ball to swing. While they improved on previous performances, they were still a bit shorter than England's seamers, who bowled 54.03% of their deliveries on a length compared to 45.92% for India.
Dropped chances cancel each other out
Both England and India dropped catches in the slips, particularly early in the series. India's dropped chances were a bit harder, but they cost the team more runs than England's did.
A win for the umpires
Of the 67 reviews taken in the series, only 11 were successful. India had just one successful review while in the field, but their batsmen did get a few reprieves from the DRS.