The 10 preflop mistakes beginners make in MTTs

If you play preflop badly, everything that follows is compromised. A hand opened outside your range puts you in postflop situations that are losing by construction. A BB defense that is too tight hands free chips to your opponent. A 3-bet bluff without a blocker loses to your opponents' 4-bets.

Over 100 MTT hands, you make a preflop decision on every single one. Preflop leaks therefore repeat 100 times more often than a bad river call. Fixing a single preflop leak has more impact on your ROI than learning 10 advanced postflop spots.

Mistake 1, opening 22-44 from UTG at 100bb. The implied odds are not good enough against 5 potential opponents holding plenty of hands that dominate your pair. Fold these hands from UTG, open them from the HJ or CO onwards.

Mistake 2, calling a 3-bet out of position with a small pair at 50-60bb. You hit your set about 12% of the time. The rest of the time, you have to fold to the slightest pressure. Set mining is only profitable at genuinely deep stacks (80bb+) and in position.

Mistake 3, 4-bet bluffing with a small pair to block. It does not work. A pair blocks almost nothing in your opponent's 5-bet range. The good 4-bet bluffs are ace blockers (A5s, A4s) and some king blockers (KQs).

Mistake 4, calling offsuit hands like K7o or J8o in the BB against a BTN open. These hands look playable but they are dominated 70% of the time when you pair up on the flop. Prefer suited hands even when weaker (K7s, J8s), which carry flush equity as a backup.

Mistake 5, 3-betting QJo, JTo, T9o from the BB. These offsuit broadways are the worst 3-bet candidates: they are dominated by the hands that call (AJ, KJ) and crushed by 4-bets. Play them as calls.

Mistake 6, never 3-bet bluffing. If you only 3-bet your monsters (QQ+, AKs), regs in position will run you over knowing exactly which hands you hold. Add 4-5 combos of 3-bet bluffs (A5s, A4s, K9s in the BB) to stay balanced.

Mistake 7, limping in the SB at 100bb. The limp gives the BB a free flop out of position against you, and you become the designated squeeze target for the regs. The SB either open-raises a standard size (2.5-3x) or folds. No limping.

Mistake 8, 3-betting the BB with anything from the SB. The SB 3-bet out of position is a risky investment: if you get called, you play the pot OOP with a range disadvantage. Limit your SB 3-bets to premium hands (TT+, AQs+) and the best blocker bluffs (A5s, A4s).

Mistake 9, open-raising 2.5x everywhere, at every depth. It is not optimal, but above all you give off tells the moment you start varying "instinctively". Pick one sizing per depth (2.2x at 100bb, 2x at 50bb, shove at 13bb) and stick to it.

Mistake 10, ignoring the effective stack. You play the same UTG range at 100bb as at 30bb. That is wrong. At 30bb, the implied odds of small pairs and connectors collapse: these hands disappear from your range. Your ranges must evolve with every stack bracket, otherwise you play behind or ahead of what the depth allows.

You cannot fix everything at once. Here is the method that works: pick 2 mistakes per week, force yourself to apply the fix over 1000 hands, then move on to the next 2.

Week 1: mistakes 1-2 (small pairs UTG, set mining out of position). Play tight, watch what happens.

Week 2: mistakes 3-4 (4-bet bluff structure, BB defense with suited hands).

Week 3: mistakes 5-6 (calling vs 3-bets, 3-bet bluff structure).

Week 4: mistakes 7-10 (SB without limping, constant sizings, depth-adjusted ranges).

To help you, play these spots in RangerPro's preflop quiz: it gives you 100 randomly drawn questions and shows you exactly where you deviate. The LeakFinder, on its side, scans your real Winamax hands and tells you which of these 10 mistakes actually cost you money.