My son is 14 and wants to be a young fast bowler. He seems to bowl quicker than most his age but has difficulty with his run up.
I don’t know much about cricket, but he accelerates quickly at the start of his run up, and I think he starts to lose momentum as he gets into his bowling action.
Can I ask for some advice on how long his run up should be and where in his run up should he be accelerating?

Hi Will,
Its always a difficult topic to discuss because of its complexities therefor I suggest an approach that's easy to understand.
The bowling run-up should be along the lines of building momentum.
Eg ( Brett Lee ). We are going to work backwards and perhaps better in the nets so get to training 1st. You may need some markers and a tape measure . Ask him to start his run up at the bowling crease bowling away from the nets building momentum along the way he should be well balanced and arms and legs are all moving towards the target and express to him when it feels the right moment to get into the delivery stride and bowl the ball.
Have him repeat and repeat until he gets some consistency then measure his run up.
Remember practice practice and practice and a good run up is an economical one.

Goodluck.

John Saint

Hi Will, they say the run up is to a fast bowler, what tyres are to a racing car. Without good tyres/run up, you can't go fast.
I would use the same process as John suggests above. I would also consider (if the environment is safe) to do this with eyes shut so the player can feel the running and the momentum they are building rather than focussing visually on an end point.
Another observation some experienced bowling coaches have made is the run up is about getting up to speed, establishing balance and then the delivery stride. As John pints out above, many bowlers run further than they need to.
1. Run to establish speed (good striding but not sprinting)
2. As soon as speed is there, think/establish balance (which may appear as a slight slow down but not always)
3. Jump straight, bowl straight

Thank you John and Bryan for your valuable advice. We really appreciate you taking the time and we've already been to the nets to put some plans in action.

Hi Will

Follow Dennis Lillee's advice. Get your son to have a marker to start. Get him to Imagine he is a manual car going through the gears, starting in first and building up through the gears, leaping at 4th gear and delivering in fifth gear. Practice whilst doing it with eyes closed so he gets an instinctive feel and you mark where he lands. Once a pattern of consistency has been developed that is the base line to work from. I personally don't think anyone should have too long a run up. If you have a 15 metre run up compared to a 30 metre run up that is 100 metres less sprinting per over and 2km over a 20 over spell. Also, do himself a favour and make sure his foot is halfway behind the line. Never having to worry about that means he will always be in the sub conscious mind rather than the conscious mind at execution.