Algorithm for the tables balancing?


#1

As the title says, which algorithm do you use for tables balancing in tournaments?


#2

Casinos when running tourneys and need to rebalance a table (or tables), they reseat players based on the seat(s) that needs to be filled. Such as: “Two behind the button”, Under The Gun", etc. An exception would be when seating the “final table” (for one). This is just a guess on my part regarding replay…

Regards.


#4

I would love to know this, as well. I don’t think the position at the table matters, since the button orbits around the table, every seat is every position at some point.

I would expect that re-balancing becomes necessary when enough vacancies occur at enough tables that you can consolidate the tables down to a smaller number of full tables. So, for example, if a tournament starts out with 9 full 9-seat tables, and each of them loses a player, rather than play 9 8-seated tables, they rebalance to 8 full 9-seat tables.

It also seems likely that if a table loses 2 or more players, then the rebalancer could try to minimize the average number of empty seats per table by pulling a player from one full table to fill one of the empty seats at one of the tables with multiple empty chairs.

I don’t know if there are other conditions that can trigger a re-balance, and this is what would be interesting to know. It seems that the players pulled for a table move when rebalancing occurs are players who either just won a lot of chips or just lost a lot of chips. I’ve only been rebalanced to a new table when I’ve just taken a big pot or lost a lot of chips on a big pot, or when the entire table is emptied.

It would make sense to try to either:

  • balance the number of chips present at each table.
  • put all the biggest stacks together at the same table.

I would think that balancing the number of chips present at each table would be the more desirable approach from a fairness standpoint – if you get stuck at a table with all low-stacked players, that would greatly limit your potential to grow your own stack. And this would tend to create a table structure analogous to a NCAA tournament seed, where the #1 ranked team plays the bottom ranked team, making it more likely that the final game pits the #1 and #2 players against each other.

As well, were the #1 and #2 chip leaders at the same table, and #1 eliminates #2, that would create a massive stack advantage for the #1 leader, making it all the more difficult for the rest of the field to compete, and this would also be undesirable from a fairness and competitiveness standpoint. So maybe a good rebalance algorithm would want to keep the biggest stacked players separated for as long as possible. But then, I have found myself at MTT where I’m in the top 5 and the other leaders are all at my table, at least a few of them. Could be that this is due to being late enough in the game where there just aren’t enough tables left to keep us all separated…


#5

I’ve been reading old posts here and ran across this
.
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MrReplay post from Oct '15

This is going to a rather long winded response, and should really be in our help section, but anyway here goes…

There are two simple rules that we check every time a player is eliminated from a tournament:

REMOVE TABLE - Remove a table if it’s possible (and redistribute the players amongst the remaining tables)

REBALANCE PLAYERS - Don’t ever allow the number of players on two tables to differ by 2+ players (move players amongst the tables to ‘rebalance’ them)

  1. REMOVE TABLE

SCENARIO: 9 seat tourney with 19 players, seated: 7,6,6. One player gets eliminated, now seated: 7,6,5. That leaves 18 players which fit in two 9 seat tables, so we remove one of the tables.

Which table to remove?

The tables with less players, so we have less balances.

Who to move and where?

Move all the players from closed tables to available seats on other tables, always respecting the ideal distribution. There is a scenario where in addition to closing some tables we also have to move players from unclosed tables, this is also to achieve the ideal distribution every time, using a priority system that matches PLAYERS with SEATS (i.e.: 10 seats, 0 = best, 9 = worst).

Based on the last hand played on the removed table, the Big Blind player is given highest priority (0 - best seat), then each seat anti-clockwise from that seat is given the next priority down (1, 2, 3, etc) until the last seat, left of the BB, which is the ‘worst seat’ (first to act) has been assigned a priority. ALWAYS based on seated position.

Finally we match the highest priority players with the highest priority seats, each in turn, until the lowest priority player is seated. Of course there may well be more empty seats than players, which will result in the lowest priority seat(s) not being filled.

Caveat: in a scenario where we need to close a table and balance another, all occupied seats from the closed table will have higher priority than those single balances.

  1. REBALANCE PLAYERS

SCENARIO: 9 seat tourney with 26 players, seated: 9,9,8. One player gets eliminated, now seated: 9,9,7. That leaves 25 players, so we can’t remove a table. Instead we must ‘rebalance’ the tables, so that there is only a difference of 1 player (max) between the tables. Hence, a player is moved from a table with 9 players, to a table with 7 players, now seated: 9,8,8.

When does the rebalance occur?

Whenever a hand ends, we check to see if we have the ideal distribution. Players are then flagged as standing in one table and sitting in another, no players stand in the middle of a hand where they are playing.

Which table to move a player from?

All tables where the number of participants is greater than the ideal.

Which player to move?

Choose the N worst seats (ie. seated left of the Big Blind player) from all tables where the number of participants is greater than the ideal. Even if the player has been moved already, he/she’ll be moved again.

Basically at the end of each hand in a tournament we try to make an ideal distribution of the participants that are still playing through the numbers of tables that are necessary for number of players based on the number of seats.

Bust-outs

If a bust-out occurs during a hand, and that table must be rebalanced after, the current priority is considered, not the priority from the future hand, which could cause a seat other than the worst to be moved.

That’s it, simple!..

Or you could simply go to the help section at the bottom of the page and you will find this


#6

Hi,

Before I opened the thread this morning, I just spent an hour finding our internal discussion on what rules we use and looks like I was beaten to it, lol. Thanks anyway, to feelmysins.

Actually, we think it matters a great deal and that’s why we give the moving players a priority. If you have just paid a big blind and get relocated, you deserve the best seat at the new table (if there are two or more open) Nothing sucks more than scraping past your big blind in a tournament, then immediately being asked to post another at a new table

These considerations initially sound balanced and fair but they would cause awkward situations.

  • Players who lose a big pot or have multiple rebuys and see the chip leader who has all the chips they paid for whisked away on purpose to sit with the other big stack would feel disadvantaged and upset.
  • I don’t think it would be easy to do, but trying engineer a move by having a certain stack size might become a thing. We would be guaranteed to get emails to Support from players saying they just got knocked out and should have been moved the hand before because they had ‘x’ chips

We do not use stack size when considering who to move. For example, if the split is 9 on one table and 7 on the other. When two tables have ‘too many’ players, like in a 9-9-7 split, the table to lose a player is chosen randomly
There might be some merit in moving a player from the 9 handed game which finishes their hand first, but again, that leaves the door open for players being able to influence the move by stalling

Rob


#7

An interesting thing about all the big stacks seemingly getting clumped together on one table is that there might be some reason for this simply due to them knocking multiple players out and causing it inadvertently.

Some observations, (which I have never really investigated much)

If a table has wild rebuys, it raises the chances of that table being higher average chips.

When two of the bigger stacks do find themselves at the same table and they don’t clash due to the fear of being damaged, it may even raise the chances of them knocking out just the small stacks and before you know it another big stack gets moved there too.


#8

What usually happens with me is I get reseated in the small blind, and have to sit out the hand.


#9

Hahah sorry chase.
I am one of those people that needs to know whether it’s the thingymabob or the doohickey that keeps the whirlygig doing whatchamaycallit so I press all the buttons on the dooberry and see where they go.


#11

There must be some reasons, the example above one of the first to come to my mind also, for the numerous (actually a majority from my experience) tables looking final tables prematurely.


#12

I cant count the # of times I either lose position or have to sit out after rebalancing, that’s disturbing.


#13

Isn’t this a good thing? especially in tournaments with antes.

  1. You get immunity from being eliminated for a hand
  2. You have a whole orbit at the table before you face a big blind

One of my theories is the small blind is probably the most likely available seat on a table to lose a player because the Big Blind or UTG are most likely to lose a player.


#14

Those are good points. I don’t mean to imply that it’s a bad thing. I just noticed that it happened to me a lot. Since the reply above mentioned that the preferred seat to move to is the button, I thought it was interesting that I’m usually moved to the SB. Which should be the second worst seat, but since you get sat out of the hand, you get the advantages you mentioned.