Bowler's mode of delivery

[srinivasan]

The law is quite clear about the bowler and Umpire's responsibility about the mode of delivery.

1). However, is it necessary for the bowler to inform the Umpire or Umpire ask the bowler at the start of every new over in the same spell?

2). What would happen if the bowler changes the mode of delivery (say from Right Hand Over to Right hand round) at the start of his new over in the same spell?

I had this happening to me once. In my case when I noticed the non-striker moving over to the other side, I asked the bowler if he wishes to change his mode of delivery.

[jaybee]

Law 24(1)(a) says the umpire is to find out how the bowler intends to bowl and to inform the striker.
The law then goes on to require the bowler to tell the umpire if he intends a change in the mode of delivery.

This is quite clear. When the bowler comes on the umpire must ask and tell the batsman. There is no need to do this at the start of each over though it would be correct to do so if the bowler starts a fresh spell.
If the mode of delivery is to change - i.e. after the bowler has started a spell - the onus is on the bowler who must tell the umpire who then informs the striker. If the bowler doesn't do this the umpire calls No Ball - in theory at least (normally you'll know, as in your case, because he'll ask the non-striker to move across and it causes less hassle to ask the bowler if that's his intention).

This happened to me once, in my playing days, when I was the striker; the umpire didn't notice and the ball seemed to come at me from nowhere - most disconcerting! Although I managed to block the ball the umpire ignored my comment that he should have called No Ball.

[wisden17]

Have very little to add to what jaybee has said, although two little things:

1) When a bowler starts a new spell, after having already bowled in the match, I try to ask something along the lines of "Right Arm over, again?", obviously if you can't remember how they bowled before in the match, perhaps not best to ask it like this.

2) I have had a No Ball for a bowler changing the mode of delivery without informing anyone. He didn't even tell the Non-striker! So he came running in, and went between the non-striker and the stumps. Certainly wasn't expecting that!!