Choose a corner and an anchor row
For a bottom-left corner, an illustrative bottom row is 128 · 64 · 32 · 16. Values decrease away from the largest tile. The exact numbers do not matter; the useful feature is a full row whose tiles cannot slide sideways into an empty space.
Build matching smaller values in the row above, then bring them down when that improves the layout. Check every affected column before doing so. A move acts on the whole board, not only the pair you are watching.
A single gap changes the safety of a move
Compare two bottom rows before moving right:
128 · 64 · 32 · 16stays in place because it has no gaps and no equal neighbors.128 · 64 · — · 16becomes— · 128 · 64 · 16before the new tile appears. The largest tile leaves the corner.
Even a full row can change when equal neighbors merge. Always simulate the row using the merge rules; do not reduce the plan to “right is safe when full.”
Recover without chasing the corner blindly
If the largest tile shifts, inspect whether a move back can restore it. A newly spawned tile may occupy the corner, so an immediate reversal is not always enough. Avoid alternating left and right automatically: each valid move can introduce another tile.
First preserve available space and prevent the board from locking. Then work the obstructing small tile into a useful merge. If a move temporarily breaks the preferred order but prevents an immediate loss, take it and rebuild later. Corner play is a planning aid, not a guarantee of reaching 2048.
Review the move that disturbed the row
For three practice runs, note the first time your largest tile leaves its corner. Was there an unnoticed gap, a merge that opened the row, or no viable alternative? These are different problems. Correct the first two by looking ahead; accept that the third can require changing your layout.
The general strategy guide covers the surrounding habits, including empty space and controlled input.
Try the next run
Use one idea from this guide in the 2048 player. Its game page includes controls and edition/source details.