Preflop Hand Income
The following graphic depicts the result of a simulation of preflop
hands against a given number of opponents. The graphic visualizes a
series of simulations, similar to those described in Denis
Papp's thesis. The actual formula to calculate the income is
described here.
A 13*13-matrix is shown. The Deuce cards are to the left/top, the Aces
to the right/bottom. Thus, the right/downward diagonal displays the
pairs. Red color means a positive income, whereas blue color indicates
a loss (in a game where each player calls the blinds and then checks
all further bets). Clearly, a pair of two Aces is a good hand to
start. Above the diagonal, the suited card pairs are shown, below the
diagonal, unsuited pairs. Thus, the pixel in the upper right corner
shows the income for a Deuce/Ace suited pair.
Papp already describes the apparent tendency to prefer big cards for
larger player groups. From the graphic, it becomes evident that also
hand pairs being suited or connectors become more important. This can
be explained by to the fact that the income is counted rather than the
chance to win a single hand (for larger tables, a single win will
produce much more revenue than a win in a heads-up game if the same
amount is bet by each player). However, it takes a stronger hand to
win, thus favouring straights and flushes. Therefore, connector cards
(adjacent to the diagonal) become more important, and you can loose
your money easily by playing with non-pair unsuited cards.
Note that the income is the result of a Monte-Carlo-simulation rather
than an exhaustive enumeration. I used a million games per hand/player
combination, but still some minor irregularities (as can be seen for
unsuited pairs with an Ace (bottom line of the graphics) for larger
player numbers) exist.
Preflop calls
Allegedly, position is pretty important in Poker, as you get more
information about your opponents before making your own call. Using
over 5 million Texas Hold'em Limit hands from the IRC Poker Database,
I build the following graphic:
This graphic shows the percentage of hands played at the various
positions. Position 1 is the small blind, position 2 the big blind,
which obviously play far more hands. The benefit of later positions
can be seen, since it seems more tempting to call a hand at a later
position, but it does not amount to much. The difference of the
11/12-player games may originate from the data, there were only a
small number of such games. Funny enough, position 3, which is the
first to make an actual decision, seems to call more often than later
positions do, althought common Poker knowledge dictates that this is
actually the worst position to have.
The following graphic shows the hole cards that got played to
showdown. Of course, this is not exactly the number of hands that
entered preflop betting, but those that didn't fold until showdown.
Actually, that is seems that those guys at the IRC channel have yet to
read their Sklansky. There seems to be little special emphasis on suited
cards, and low pairs are way too common. Recall that this is only the
cards that reach showdown - suited cards that have not met their flush
will be folded by now (here, suited cards are in the lower triangle).
This graphic shows the preflop activity, i.e. the number of raises. It
is not very exact and the data is not very conclusive, but it seems
that both very strong and very weak hands get lots of action. The
latter may be explained by the fact that they are played by the blinds
only, and those always have at least two actions during preflop
("Bc"), hence the apparently heavy action during preflop. I need to
adapt the data here -- consider it corrupted by now.