Perhaps I'm just confusing myself needlessly... but humor me for a bit.
First scenario. Suppose you see that a player has counted out a stack of chips near his chip stack -- say 15 T100 chips -- and then holds them in his hand. It is now up to this player to check or bet. The player extends his arm fully with the stack of chips in hand as if to place a bet (clearly over any "imaginary" betting line, if there was one), and then brings the whole stack back, and then checks. In my mind, this is the classic "pump-fake", and if the house uses a "forward motion" rule, I am guessing that the TD would likely rule that all 15 chips must be committed to the pot. If the house uses a "chips released" rule, or perhaps where there is no rule either way, I expect that it is possible that the TD could sometimes rule the same where the action looks so blatantly "angle-shooty" - that this type of action could be ruled a bet of the full 1500. I think I would be OK with this.
Different scenario. Suppose you see that the player holds these 15 T100 chips in his hand, the blinds are 50-100. It is now up to this player to check or bet. The player extends his arm fully with the stack of chips in hand and drops one 100 chip on the table, and then after a short but noticeable delay, drops two more 100 chips on the table. In my mind, this is the classic "string bet" -- multiple actions being used to place chips in the pot -- and the dealer can enforce the rules and hold the player to a bet of 100. I think I have no problems with this either.
The question that I have is -- and perhaps I just need to work this out in my head -- is there an easy way to determine which of these two scenarios should apply in a given situation? In the second scenario, a "string bet" is called, but couldn't someone just as well argue and rule that the bet actually should be the whole 1500 since all of the chips were initially moved forward into the pot?
I can imagine variations of the situation where there are timing differences between the "pump" and the "drop" "drop" of chips, where there is no doubt that the player's intention was not made clear, but where I would find it difficult to determine definitively that the bet should 1500 or 100.
Thoughts are much appreciated.