Biggest tossup in NBA playoffs?

Updated: May 13, 2013, 11:24 AM ET
By Kevin Pelton | ESPN Insider

The first conference semifinal series to go four games, Spurs-Warriors, remains deadlocked, but this past weekend offered some additional clarity on which teams might square off in the conference finals starting next week. Let's take a look at all four series, ranking them from "most certain" to "most wide-open."