Poker Software and Analysis

Following on from How Accurate Are Your Statistics, we shall now analyse the number of hands we require in order to confidently assert that a player is too loose.

The most common statistics used to measure a player's tightness are Saw Flop % (SF) and Voluntarily Put In Pot % (VPIP).

• SF is the percentage of hands where a player saw the flop.
• VPIP is the percentage of hands where a player saw the flop, excluding the big blind.

Poker Edge states that 33% is too loose, 18% too tight (source). This is for 9 or 10 player tables.

So, one way to find loose players is to find players who play more than 33% of hands.

From How Accurarate Are Your Statistics, we already know that:

p ± 1.96 x $\sqrt{\frac{p(1-p)}{n}}$

Therefore, the lower confidence interval is:

L = p - 1.96 $\sqrt{\frac{p(1-p)}{n}}$

So

L-p= - 1.96 $\sqrt{\frac{p(1-p)}{n}}$.

And thus

n=pq${\left(\frac{1.96}{p-L}\right)}^2$ .

So, using the above, we can calculate the number of hands we need if we want the lower bound to be L, for a given p.

Table one shows some pre calculated results for the minimum number of hands required for an observed VPIP, given that we want a minimum VPIP of 35%.

Example 1

For example, if Poker Office indicates that a player has a VPIP of 44%, then we'll need atleat 117 hands of data, if we wish to be 95% certain that the player really does play over 35% of hands.

Is Mr Elnur a loose player?

Example 2

From the Livetracker screenshot, we can see that Mr Elnur saw 49% of flops in the 45 hands present in the database. From Table 1, we can see that for players who've seen 49% of flops, we need 49 hands of data before we can be 95% confident that they see on average over 35% of hands. 45 is less than 49. So we cannot conclude that Mr Elnur is a loose player whom we want to play against.

Potential Issues

However, these figures need to be taken with a pinch of salt, as there are some problems with the assumptions.

• Do Poker players play consistently? The answer is probably not. As all players will modify their game over time as they learn and attempt to improve their skills.
• Good players will adapt their game to current conditions. Depending on how tight a table is, their play may be tighter or looser.
• The mathematics assume that every hand has an equal chance of being played. However, good Poker players tend to play fewer hands from early positions, and more hands from later positions.