Princeton Election Consortium optimized picks
Picks optimized for maximum return-on-investment for federal and state legislative races. These detail (a) the marginal races most likely to determine control of the U.S. Senate, and (b) legislatures where Republican wins are most likely to break single-party control over redistricting in 2021.
November 21 update: control of the Senate comes down to two races in Georgia. This is a simple situation.