Expert Minesweeper (30×16, 99 mines) has a mine density of about 20.6% per cell. That's meaningfully higher than intermediate's 15.6%. The additional density changes how the game plays — patterns are tighter, chains of safe deductions are shorter, and forced guesses happen in roughly 30–40% of games regardless of how well you play.
Winning on expert consistently is about minimizing unnecessary guesses, not eliminating all of them.
On expert, the goal of the opening is to clear as much territory as possible before hitting numbers that require work. Click in the center first. If you get an empty region, click near the edges of it to spread the cleared area. The more numbers you expose early, the more cross-referencing opportunities you get.
Don't get absorbed into solving one corner while the rest of the board is unknown. Work across the board to build up context.
On expert, your opening move has a ~1-in-5 chance of hitting a mine if you're unlucky. Some expert players accept fast deaths and restart quickly rather than playing carefully from move one. If you're going for completion rate rather than speed, slow down and verify each deduction before clicking.
At 20%+ density, numbers 2 and 3 appear much more than on beginner/intermediate. Patterns that involve 2s and 3s are important to recognize:
With 10–15 mines remaining and 25–40 unknowns, the global mine probability is 30–40%. Unknown cells near known-mine clusters often have lower local probability. Unknown cells in untouched regions have roughly global probability. Prefer the locally-constrained guess if forced.
If you play 100 expert games and apply all logic correctly, you'll still lose roughly 30–40 of them to unavoidable 50/50s or similar. This is a property of the puzzle, not a reflection of your skill. The target for expert isn't 100% win rate — it's 60–70%, with higher being genuinely impressive.
When you hit a forced guess, pick the cell that opens the most territory if correct. Then accept the result and either continue or restart.