S.F. Chronicle Top 20 Boys and Girl basketball polls The Chronicle’s preseason boys and girls basketball rankings are always full of surprises and new teams, largely because the landscape of talent changes each school year. Moreau Catholic-Hayward boys, after a disappointing blowout loss to end last season to Serra, jumps from 10th in 2014-15 to the top spot this season. The Mariners didn’t lose a single senior to graduation and all five of their starters have been so for either two or three seasons, including four-star recruit Oscar Frayer, a high-flying 6-foot-7 wing who last week de-committed to Cal. Last year’s No.