Not everything went as expected Saturday, the first day of the United States Women’s and Junior Championships, which are being held concurrently at the Chess Club and Scholastic Center of Saint Louis.

All the games among the women were decisive and, with one minor exception, all the higher-ranked players won. But the favorites among the junior players both suffered setbacks. Ray Robson, the top seed and the only grandmaster in the tournament, barely managed to draw against Eric Rosen, a master and the lowest-ranked player in the event, while Samuel Shankland, an international master and the No. 2 seed, lost to Parker Zhao, another master.

Shankland’s loss may not have been as surprising as it appeared. Though he is only 18, he has said recently that he is done with playing chess competitively and he is “retiring” after this tournament.

The two championships are 10-player, round-robin events in which each player faces all the other competitors once.

Though there are large differences in the rankings of the top and bottom players in both events, the early struggles by the top juniors suggests the tournaments could be quite competitive. And if the high number of decisive results in the first round is any indication, the tournaments will also be very entertaining.

The games can be followed live online. Round 2 on Sunday is at 2 P.M., central daylight time.