Suppose, in tournament we have Prize Payout is 10 and 20 Player left on 4 tables. Out of 20 Player, 10 go allin in 2 tables and in rest 2 table game are just to start, so in that case do we need to start the bubble? If yes, then what if only 3 player eliminate from the tourney, do we need to continue with bubble or just stop the bubble ? If we stop the bubble then we create bubble in tournament multiple times. Please give your pro-level feedback, which is as per industry standard.
< TL;DR >
- Bubbles and Hand-for-hand play are not the same thing, although hand-for-hand play is most often imposed right before the bubble bursts.
- You shouldn't have 20 players over 4 tables, unless it's a 6-max tournament.
- I wouldn't expect H4H to begin on the basis of any number of players being all in, just based upon the number of players remaining in the tournament.
- There's no fundamental problem with a tournament entering H4H multiple times, but I wouldn't expect it in the way you describe (starting H4H because a lot of players are all in, then cancelling it once very few/none of them bust).
< /TL;DR >
Firstly, as Herb Wolfe mentions in his comment, there is some confusion here around the terminology, so let's clarify:
Bubble In its purest sense, the bubble is the point in a tournament at which the next player eliminated will be the last player to receive no prize. So if you're tournament pays 10 players and you have 11 players remaining, the tournament (and therefore the 11 remaining players) is/are "on the bubble".
The term has been expanded over time to also include other milestones in a tournament, such as the point where the next player eliminated will be the last to receive a certain level of payout, or the last to not make the final table (known as the "final table bubble").
Hand-for-hand This is a mechanic to allow for easier administration of player exits at key points in a tournament, including often on some of the bubbles described above.
The concept of hand-for-hand play is that all tables complete the current hand before proceeding to deal the next hand. This ensures that the speed of play at one table or another does not affect the number of hands seen in a given time and therefore provide a benefit or disadvantage to anyone.
For example, without hand-for-hand play, a short stacked player on the bubble may decide to take a long time with every decision, resulting in other tables playing more hands and so increasing the chances of someone else busting on the bubble instead of him. A lack of hand-for-hand play at key points in a tournament can lead to this behaviour occurring at multiple tables (or even all tables) and the tournament therefore grinding to a halt, which is obviously not in the interest of the venue providing the tournament as they have to allocate staff to run the tournament (dealers, floor etc) and the longer the tournament runs, potentially the more it costs them to run it.
Hand-for-hand play also makes it easier for tournament directors and their staff to identify the order in which players have been eliminated, which is important around any prize jumps and the pure bubble itself to make sure that people get paid the right amount.
So, now on to your question:
Firstly, you ask us to presume there are 20 players left on 4 tables. This should never happen in a well run tournament (unless it is a 6-max tournament) as tables should be broken as soon as it is possible to do so, keeping the number of tables to a minimum. This is both for the benefit of the players (balanced and maximum numbers of players on each table) and the venue (reduced running costs). So with 20 players remaining, I would expect there to be 2 tables (10 players on each) if playing 10 handed or 3 tables (two with 7 players and one with 6 players) if playing 9 handed.
Putting this aside, you then essentially ask:
What should happen if enough players are all in across some subset of the tables remaining such that if they were all eliminated, the bubble would be broken? Specifically should play at the other tables be halted in preparation for hand-for-hand play?
The exact criteria/rules for making the decision of when to start hand-for-hand play varies from venue to venue and even between tournaments within the same venue sometimes. However, the general approach is usually the same:
Start hand-for-hand play as soon as it becomes apparent that a significant point in the tournament could likely be reached within the next few hands.
So, if you have 11 players at 2 tables remaining and are playing to a final table of 10, it would be appropriate to start hand-for-hand, as when the next player is eliminated, the two tables will be merged into one, seats re-drawn for at least some of the players, etc.
Equally, if you're running a $100 tournament and there are 33 players remaining, with 33rd place paying $1000 and 32nd paying $1500, this could also be considered a significant point and thus hand-for-hand should commence.
In your specific example, I would suggest that play at other tables should not be halted until the outcome of the hands where 10 players are all in has been established. You can then judge whether you are close enough to the bubble to justify moving to hand-for-hand play. This also answers the second part of your question, about whether hand-for-hand should then be revoked if only a small proportion of the all-in players bust, as you wouldn't start hand-for-hand until you knew how many busted from those hands.
If the rather unlikely scenario you describe occurs and all of the players who were all in are eliminated, you obviously have no problem and there is no need for hand-for-hand, as the bubble has been burst exactly. The only exception would be if shortly after this bubble there is a significant pay jump or a final table bubble, in which case, hand-for-hand play may be imposed anyway.
With regards to:
If we stop the bubble then we create bubble in tournament multiple times.
If by "bubble" you actually mean "hand-for-hand play", then this is fine. It's common for a single tournament to enter hand-for-hand play multiple times at different points, especially if the tournament is very large.