Checkers have been solved 16 years ago and still see competition. A game being solved is not exactly the same as "apply this memorizable algorithm and you'll win", especially if the solution implies scanning 10^n positions for each move.
Say, allowing a purpose designed device, but limited to 1W of power consumption. Or some fixed energy budget (J) per move. Too strong? Take it down to 0.1W, 10mW or whatever.
That would degrade brute forcing as a viable approach, and bring it back to smart algorithms, clever ways to reduce the search space, etc.
From the computer point of view, it's more possible states to explore, so I think it makes things much harder