Grass season is back, and tennis stars are in a race against time on the slipperiest surface

Queen’s, LONDON — Less than a week after the end of the French Open, and just three weeks before Wimbledon, it is raining in west London. At Queen’s, a men’s and women’s tournament two rungs below a Grand Slam, players trying to make the most of their limited time to adapt to the most specialized surface in tennis are waiting for the clouds to clear. Having spent the previous two months on clay, some of the top women’s and, next week, men’s stars are shifting into grass mode. Victoria Mboko, the