Fast bowling is hard work. Period. There are no two ways about it. If you want to be a fast bowler, you need to build stamina, strength (both physical and mental) and a surprising amount of selectiveness as you choose to ignore some tips and imbibe others.
Ishant Sharma, India's premier fast bowler who has been the butt of many a joke after his part in James Faulkner's spectacular match winning innings, has been through many coaches. Shrawan Kumar, his club coach, Manoj Prabhakar, his Ranji coach, Waqar, his Sunrisers coach and the Indian coach Joe Dawes.
Some argue that wickets come when technical problems are solved. It can also be argued that when wickets come, technical problems hardly matter. Ishant's problem is as much mental as it is technical.
Everyone knows about Ishant's wrist position and how his wrist is not perfectly behind the ball. Most of his deliveries leave the hand which is pointing towards fine leg.
For an inswinger, the fingers are generally pointed towards fine leg but the palm and the wrist remain straight behind the ball.
Everytime he bowls, Ishant believes he is bowling an inswinger. The ideal pitch mark for an inswinger is just outside off, for which the ball needs to be aimed further outside off. The length needs to be such that the ball hits the top of off, exploiting the gap between bat and pad or forearms and body. For a right arm inswing bowler, bowling to a right handed batsman, the full length ball is hardly useful. It would take the inside edge, running down to fine leg for a boundary or a few runs.
Hence, to be on the safer side Ishant prefers to drag the ball down a bit. If the ball were on off stump, it still makes a good delivery to which the batsmen can either defend or play the backfoot punch. But since he hopes the ball will swing, he pitches it outside the off. With no swing coming to his aid, the ball ends up short and wide making the cut shot playable.
The thing about swing bowlers and wicket taking bowlers is that they don't really know where to bowl when there's no swing on offer. Bowling line and length takes tremendous patience. The batsman isn't going to gift his wicket on the first ball that's pitched just outside off on a perfect length. Since Ishant has been tagged as the 'leader' of the attack, he believes his job is to take wickets and like Ashwin, perhaps tries too much in order to get one.
He has begun to develop the outswinger as well. He has tried a few. He most likely is aware about his wrist position but is at a point where he believes no one understands what he is going through. Hence, advice givers are like bees buzzing in his ear. He will choose to ignore. After games like the 3rd ODI, a bowler seriously questions himself.
Yes, he didn't bowl yorkers. He bowled short and got smashed.
But he doesn't need people telling him how to bowl. He needs people telling him where to bowl.