Build a better approach
Slide Nine is a three-by-three sliding puzzle. Eight tiles and one gap. Tap a tile that shares an edge with the empty square to slide it in. There are no diagonal moves and no jumps. Every shuffle is made from legal slides, so a solution always exists.
The empty square is a tool. You move it to where a tile needs to go, then pull that tile in. Randomly sliding whatever is convenient shuffles the board into a harder mess. Decide which tile belongs next, walk the gap to it, and place it.
Turn information into decisions
A reliable order is the top row first: 1, then 2, then 3. After that row is correct, do not break it. Solve 4, 5, and 6 next. The last three tiles have little space, but they are easy if the rest is already locked. Solving the last row first is how people trap themselves.
There are no lives. Time and move count decide the score. A scramble you no longer understand is worth a reshuffle. Mashing to “see if it pops out” usually costs more moves than starting a clean plan.
Practice for consistent results
If two tiles in the last row are swapped, cycle them with the gap rather than tearing the middle row apart. Short cycles beat a full reboot. Pause when you feel hurry; hurry is just extra slides.
Drill: one board with top-row-first, timer ignored. Second board, same method, then look at the clock. The method is the skill. Speed is a side effect.