If a captain was asked to put down what he most wants from his bowlers, they'd read something like this: 1. Wickets, 2. Economy, 3. Discipline
Over the years, Indian captains have never had the luxury of their wishes being anywhere close to being granted by their fast bowlers. At most, they would have one bowler ticking the boxes, but invariably they would have to compromise on the rest of the attack. One would provide wickets but they would always come at a cost. Another would be disciplined but his wickets column wouldn't make pretty reading. It was usually a toss-up between rudderless aggression and a modicum of control.
This tells you why Ishant Sharma has had the long but less-than-fulfilling international career he has had. Even though he didn't take wickets as often as the captain and the fans expected, he provided the control and predictability that a captain always wants, and that's why there haven't been too many breaks in his Test career. He has always been the workhorse an Indian captain looks for, especially overseas.
In the subcontinent, fast bowlers have a fairly limited and defined role to play - bowl with the new ball (more in the hope of taking wickets than belief), bowl a restrictive spell before the ball starts reverse-swinging, and then one or two incisive spells once the ball does indeed start reversing.
This lack of belief about picking up wickets with the new ball invariably shapes you as a bowler. You prefer bowling lengths that aren't conducive to swing bowling, for the new SG Test ball rarely moves in the air, and playing on the up and through the line on full-ish deliveries isn't seen as being as risky as it is in South Africa, England, New Zealand and Australia.
It helped that Ishant was never a swing bowler and that his natural length was the ideal length to bowl defensively with the new ball. His strengths were his height and the high-arm action that ensured he got extra bounce from the surface (the point of release is directly proportional to the bounce you get after pitching), which also made bowling a little shorter more sensible. The combination of his strengths and the fact that the majority of his Test cricket came at home meant that Ishant didn't invest time in developing a new skill. Maybe he didn't have to.
He also happened to be among the rare breed of Indian fast bowlers who would give his captain 18-23 overs of discipline with regards to economy every day, day after day. It's an asset that doesn't get quantified by cold numbers, for bowlers are generally judged by strike rate and average in Test cricket. But the value Ishant brought to the table was never lost on his captains.
There are a number of similarities between Ishant and Stuart Broad. Both are tall, hit the deck hard, and are predominantly seam (not swing) bowlers. Ideally both of them should have similar figures in countries with conditions helpful to seam bowling, but that's not the case. Broad has taken more wickets at both a better strike rate (55.4 to Ishant's 71) and average (27.8 to Ishant's 41.1). Even if we were to discount the fact that playing more than half his cricket in England will have helped Broad's confidence, the difference in the effectiveness of both bowlers has been stark. So what is it that Broad does that Ishant isn't or wasn't doing?
The key to Broad's success is his ability to roll his fingers over the ball just about enough to make it move laterally away from the right-hand batsman after pitching. The control with which he can bowl legcutters allowed him to bowl fuller, and also he bowls in the channel that makes batsmen poke at it.
On the other hand, Ishant would mainly bring the ball back in after pitching, with the odd ball straightening occasionally - and since that didn't happen at will, it wasn't possible for him to use the incoming deliveries to set up the caught-behind dismissals.
The problem with bowling a lot of legcutters is the lack of control over the genuine inswinging delivery, because the muscle memory of wrist and fingers doesn't allow the ball to be delivered with the seam bolt upright. Broad had his issues with this and Ishant too went through an extended phase where, no matter how hard he tried, the ball simply wouldn't come out of his hand with the seam upright. So much so that in some ODIs, he bowled only cross-seam stuff.
About seven months before the tour to England, Ishant rediscovered the magic formula to keeping the wrist firmly behind the ball. Now the seam was no longer scrambled after release, and that one change made a significant change in the way he operated. He looked a lot more in control of what he was trying to achieve - though the ball wasn't swinging still and his length was still a little short.
The difference was seen in the Test match against Afghanistan, where the ball wasn't just seaming after pitching but genuinely swinging in the air. This was the first time I saw Ishant make the ball move laterally in the air consistently.
He had also started bowling a lot fuller. Earlier, the bounce he generated made him look a lot better than he was actually bowling, because the batsmen would either leave or get beaten, and the keeper would collect the ball with his gloves pointing upwards. While that looks pretty on TV screens, it's not effective enough to take wickets. By bowling fuller and swinging the ball in the air, Ishant not only made batsmen look for the deviation but also got lbw and bowled dismissals into play.
He also had a leg-side catching trap against Afghanistan: a short midwicket and a catching fielder just behind square, which spoke of the hard yards he had put in on the county circuit. He seems more aware of what he was doing and the possible outcomes.
In the current series in England, about 20% of his deliveries have been full, compared to only 8% in the 2014 series. Batsmen can no longer leave his deliveries on length, for significantly more balls are finishing within the line of the stumps.
Now that he is able to swing the ball, the next step should be developing the ability to roll his fingers once in a while to extract away-going movement after pitching. The day he starts doing that at will, his incoming deliveries will be more potent. Ishant is almost 30, and if anything, will get a little slower in the air as he goes along. Developing the ability to swing the ball will not only make him more effective but will also help him prolong his career.