How to check if the bowler is throwing instead of bowling in cricket?

Question

How to check if the bowler is throwing instead of bowling in cricket? Is there any technology for checking throw bowling in cricket?

Answer 1

If we say the bowler is literally throwing the ball for example like this:

^{Source: ESPNCrickinfo}

then the umpire shall declare it as a No-ball imminently.

If we say the bowler bowls throw balls in bowling action. That means he is running and performing the same action as bowling like this:

^{Source: Wikipedia}

but not bowling properly (i.e. still throwing the ball), then if umpires catch such action during the match (that is totally up to them) they can call it a no-ball immediately. However, even if they don't catch such illegal bowling actions, the report for the illegal bowling actions is generated by match officials. If any illegal action found they submit the report the the relevant team manager. And process further. You can check the full procedure on Illegal Bowling Actions ^PDF.

Answer 2

Throwing in Cricket

A ball is fairly delivered in respect of the arm if, once the bowler's arm has reached the level of the shoulder in the delivery swing, the elbow joint is not straightened partially or completely from that point until the ball has left the hand. This definition shall not debar a bowler from flexing or rotating the wrist in the delivery swing.

Bowling Action

A guideline was introduced to allow extensions or hyperextensions of angles up to 15 degrees before deeming the ball illegally thrown.

What Happens Next?

A bowler will be wired up with number of sensors, and Biomechanics experts - Human Movement Specialists monitor the action.

Update

Quoting ESPNCricinfo

If the arm is bent at the onset of the delivery stride but remains rigid or does not flex or extend beyond the permissible 15 degrees during the duration of the stride, the action is not illegal. An action is only illegal if the arm flexes or extends beyond the permissible limit while in the delivery stride.