GTO Chart Anomalies?

[Scotty]

Does anyone have any insights into these seeming anomalies in the GTO charts we're all working with?

Question 1)

In the 100bb/12.5%ante charts, the BB is tighter vs. a BU raise than vs. a SB raise. This makes sense. BB has position over SB, and SB typically has a wider range than BU.

But in the 15bb/12.5%ante, 25bb/12.5%ante, & 40bb/12.5%ante charts the opposite is true. BB is tighter against SB raises then against BU raises.

Why?

Here are some of the charts in question, 40bb charts first then 100 bb charts:

[Scotty]

Question 2)

The 100bb/12.5%ante charts differ from the 100bb/0ante 6-max charts in some pretty major respects. Does the 12.5% ante make that much of a difference? It seems like the differences are way too large to be explained by just the antes.

For example (9-handed first then 6-max):



Anybody have any ideas about this?

[Scotty]

Question 3)

In the 40bb/12.5%ante charts, why are we calling K6o in the BB vs. a BU raise, but folding A6o and K7o? Wouldn't either of these be a better choice?



There are more of these seeming anomalies, but you get the idea.
I'd love to hear your insights on any of this.

[Binkley]

Here are my guesses:

Question 1) I believe there are two reasons for BB calling tighter vs SB at 40BB and below. First, as stacks get shallower, positional advantage is lower. OOP can more easily realize equity at the lower SPR with shallower stacks. Second, the charts assume that the in position player will use a 2.5 BB raise size and out of position will use a 3.5 BB raise. So when faced with a larger bet size of 3.5 BB from the sb, and at shallower stack depth, BB will continue with a tighter range. Faced with a 2.5BB and with the ability to more easily realized equity, BB can call BN open wider at shallower stacks.

Question 2) The 100BB 6-max charts are geared toward cash games and accounts for a rake and lack of antes. Combined these two factors are significant enough for the differences.

Question 3) Since A6 gives you less straight possibilities it's often the first Ax to remove from your range. I suspect that the solver had a mixed strategy for K7, K6, and K5. But instead of using a mix, the chart just gave K6 as a 100% call and K7/K5 as 100% fold.

[Scotty]

Thanks Binkley. Your answers to Q1 make a lot of sense.

Are you sure that there's a rake factored into the 6max, but not in the 9h charts?
If so, I'm not surprised that the combo of rake and no ante makes a difference, but I'm still really surprised that makes as big a difference as the charts indicate. Wow.

RE Q3, that simplification process makes sense, but I don't understand how the result it gives does.

If you had to choose between playing A6o and K6o in the above scenario, the only reason I can see to choose the K6 is that the UTG raiser raises with more A7+ combos than K7+ combos, thus your A6o is more likely to be dominated than your K6o. But if this is the logic, what possible reason is there to EVER choose the K6 over the K7? It can't be explained by assuming UTG's raising range is more likely to contain 77 than 66 because K7 is better vs. 77 than K6. K7 is better vs. any range than K6, right?

Could it have to do with "board coverage?" I.e. our overall range would have too many 7s and not enough 6s if you chose the K7 instead of K6. But why does that matter?

Thanks for the help. Still confused.