Let's make some few examples to try to be sure we all agree please:
Let's keep the example of the BB player with 2x25 (the BB) in front of him / all fold but the button raises at total 600 / the BB acting silently.
1) BB pushes 1x1000 ---> It's a CALL (#48) ---> 450 back to him.
Yes, a 1000 single overchip call
2) BB pushes 2x500 ---> It's a CALL (#49) ---> 450 back to him.
Yes, because both NEW chips (the two 500's) are needed to make the call, and the prior-bet chips are not disturbed.
NOTE: if you disturb the prior bet chips then you are making a new multiple chip bet of all chips, that's key to understand. Also key to your "lost" example A at bottom3) BB pushes 8x100 ---> It's a CALL (#46) ---> 250 back to him.
Yes, this is a total bet of all chips because you can pull at least one of the smallest new chips back and still have the call amount. THEN you go to Rule 50 (Multiple Chip Bets) to determine if it hits the 50% threshold of a raise. If not it's a call. The minimum total bet threshold for raise here is 600 + 550/2 = 875. The player has pushed out 850 silently, hence it's a call.
4) BB pushes 9x100 ---> It's a RAISE (#46) ---> 200 must be added.
Yes. Same reason as #3: player has pushed out total of 950 silently so they have hit the 875 raise threshold in Rule 50. They must add 200 to bring up to a full total min-raise of 1150.
5) BB removes the 2x25 and pushes 1x1000 ---> It's a CALL (#48) ---> 400 back to him.
Yes. Player faces a total bet of 600, he tosses out a single overchip silently, it's a call.
6) BB removes the 2x25 and pushes 2x500 ---> It's a CALL (#49) ---> 400 back to him.
Yes, player makes a multiple-chip bet. Pulling back just one of the smallest chips (one 500) leaves less than the call amount, so it's a call. FWIW, this is the "Barry Greenstein Rule", formally adopted at the 2011 TDA Summit although it had been in use at certain venues prior to that.
7) BB removes the 2x25 and pushes 8x100 ---> It's a CALL (#46) ---> 200 back to him.
Right, silent multiple chip bet, go to Rule 50 (not Rule 49 as it says in error in the Illustration Addendum!), it doesn't hit the 50% threshold (875), so it's a call.
BB removes the 2x25 and pushes 9x100 ---> It's a RAISE (#46) ---> 250 must be added.
Correct. A multiple-chip bet, pulling back just one of the smallest chips leaves more than the call amount, so you go to the 50% threshold (875). 900 exceeds 875, so it's a raise to 1150 total.
But then comes some cases were I'm still lost:
A) BB removes only 1x25 ---> That's were I'm lost if to compare with my exemples! In my example #5 it was a CALL when he removed the 2x25 but in your answer it's a RAISE when he removes only 1x25 right? And why? And what about the examples #6 #7 #8 in the same condition?
Two different bets.
1: pull back both, you're making a single overchip bet.
2: pull back just one: See the underlined red discussion in #2 above: the prior-bet chips are disturbed and new chip(s) added... hence it's a silent multiple chip bet of all chips. Go to the 50% standard.
B) Do we agree that we will never allow the BB to remove (silently) any chips AFTER any bet: Those chips will be placed back and the normal rules applied whatever they are (#46 #49 #50) right?
That's theoretically correct. Whether it happens in every case in practice is another story. For example, player has some chip(s) in his hand and some prior bet chips in front of him, he's facing a raise of X, sometimes a player reaches out and puts chip Y in and pulls chip Z out in order to get his bet right... do you force him to leave everything in? Theoretically you probably should, but if he does it without any pause some might use judgement there and allow it.
C) BB has previously put 1x500 as BB / raise of total 400 from the button / then BB pushes silently 2x25 ---> It's a CALL by rule #46 right?
It's a total silent bet of 550. The 50% silent min-raise threshold is 400 + 350/2 = 575. The player has only pushed out 550 so it's a call and 150 is refunded.
D) BB has previously put 1x500 as BB / raise of total 400 from the button / then BB pushes silently 3x25 ---> It's a RAISE by rule #46 right?
Right, same reason as C above, he's hit the 575 threshold so has to make it a total of 750.
Thanks for the great examples!
NOW, This issue has been debated at length with every imaginable example at the 2013 and 2015 TDA Summits. Finally the cases in the Illustration Addendum were adopted in 2017. The reality is that every case may not be enforced 100% of the time exactly according to these illustrations. So you always go back to Rule 51-A: "... several possibilities exist, so players should verbally declare their bets before putting out new chips on top of prior bet chips not pulled in". If they don't verbally declare, then it's player's responsibility if the house rules other than the player intended.