Tablebases

t. In 1977, Thompson showed up at the World Computer Chess Championship th a new creation, a database that played the king and queen versus king and rook endgame perfectly. (KQKR is the abbreviation.) It wasn'1 an engine; there was no thinking required. Thompson had generated a database that essentially solved chess backwards, what we call retrograde analysis. It started from checkmate and worked its way back until it contained every single possible position with that material balance. Then i...

 Null Move

Called the "null move" technique, it tells the engine to "pass" for one side. That is, to evaluate a position as if one player could make two moves in a row. If the position has not improved even after moving twice, then it can be assumed that the first move is a dud and can be quickly discarded from the search tree, reducing its size and making the search more efficient. Null moves were used in some of the earliest chess programs, including the Soviet Kaissa. It's elegant and a little ironic...

 The Economic and Cultural Divide in America

For most of the last century, wages in poorer parts of America rose faster than wages in richer places, as inventions were put to work in the hinterlands. After Henry Ford invented the Model T, for example, workers on assembly lines all over the Midwest built it. Now it’s just the opposite. Bright young people from all over America, typically with college degrees, are streaming into the talent hubs of America—where the sum of their capacities is far greater than they’d be separately. ...