Where Clause

The where clause is an optional boolean predicate that filters trials before they reach the selectors. It is evaluated after sampling and before the selector expression. Trials that fail the predicate are discarded and not counted in the aggregate.

select avg(equity(hero))
from   game='holdem', hero='AhKh', villain='**'
where  hasTopBoardRank(hero, flop)

This computes hero’s average equity conditional on flopping top pair.

What it can contain

The predicate is an arbitrary boolean expression:

• Function calls returning TBoolean — e.g. nutHi(hero, flop), pocketPair(hero).
• Comparisons — e.g. equity(hero) > 0.5, handType(hero, flop) = flush.
• Boolean composition — and, or, not, plus ( ) for grouping.

where equity(villain) > equity(hero)
  and minHandType(hero, turn, pair)

When the where clause helps

A where clause is useful when you want a conditional probability or expected value. For example:

-- How often does hero win when villain hits the flop?
select count(wins(hero)) as heroWinsGivenVillainHits
from   game='holdem', hero='AwAx', villain='**'
where  not (handType(villain, flop) = highcard)

If you need the unconditional probability or expectation, omit where.

Filtering Cost

A trial that fails the where predicate is wasted work — the runner counts it as a failed sample but does not feed it into selectors. If your where clause matches very rarely, the simulation may take a long time to gather enough successful trials. Tighten the from clause (e.g. fix more cards) when possible.