Approaches

Constructive and reservoir policies

Build structures that pay off later and survive repeated row rises instead of taking only immediate points.

Retunes an existing policy for survival milestones instead of average score while changing nothing else. The result barely moved.

Look a few moves ahead, take the best column on your own turns, and average over every sampled disc the game might deal.

Instead of judging a column by its average outcome, judge it partly by its worst outcomes, and find that the resulting policy dies much sooner.

Scores visible board traits, adds them together, and plays the highest-valued column.

Play normally on a healthy board, then switch to worst-case thinking when height, crowding, or covered discs put the game at risk.

Clear numbered discs and open covered ones fast enough to keep the board from filling.

Ranks columns partly by their worst imagined futures. Every tested risk setting trails the baseline.

Judge a move by how much longer the game will still last, rather than by how many points it scores right now.

Adds one human rule to the depth-4 search by refusing risky drops above a disc's vertical safe zone, then tests whether the rule extends life.

Instead of searching ahead, train a model on past games to judge a board or pick a column, and learn why that kept failing.

Learn the whole spread of how long a game might last, and only leave the safe move when the evidence says so.