Some years ago Andrew Seidman who was also known as “Beluga Whale” and one of the best online poker pro’s around at that time devised his now famous “Beluga Theorem”.
This poker theory stated that if you were holding a one pair hand and you were raised on the turn then you would need to severely assess your holding, clearly before we continue then this theory cannot apply to playing free poker as in play money games.
For example let us say that you have a hand like Ad-Kc and you make it 3.5bb to go from middle position. A player to your left calls you and we see a flop heads up.
The Flop Texture
The flop comes As-10c-9c and you c-bet for around 5.5bb and are called! Both you and your opponent had 100bb effective stacks before the hand started.
The turn card is the 4h and you make it 14bb into the 19bb pot and are raised to 45bb. As a standard one off play then you have to fold your top pair top kicker hand here.
Your opponent is clearly saying that they can beat that hand. While you may rationalise to yourself that your opponent may be on a draw, in lower stakes games especially then you more than likely show a long term profit folding against these raises.
I would say that certainly within a full ring environment then the Beluga Theorem holds true at levels like NL50 and below.
In fact even in many games at NL100 then you would be well advised to fold top pair and top kicker to a turn raise.
Playing Stronger Opponents
However it is when you start to play against better opposition that the Beluga Theorem falls down. These opponents will be watching you and so a playing pattern of raise-bet-fold will be ruthlessly exploited.
In fact if your opponents always know that you will always fold hands as strong as top pair with top kicker then you will be walked on by better players.
Weaker players though in lower stake levels will simply not make that kind of play on a bluff or semi-bluff and certainly not for so much money. With a 100bb effective stack then villains turn raise is pot committal.
This is good aggressive play against weak-tight opponents but if you always fold to this line then you are in danger of becoming weak-tight yourself.
So in my opinion then the Beluga Theorem is one of those theorems that have stood the test of time but certainly only below NL50 and probably NL25 at six max play. At higher levels against high level thinking opponents then you simply cannot be this exploitable.
However I would have no hesitation in advising players to study the Beluga Theorem and to implement it into their games at NL50 and below.