FanGraphs JUST published an article telling the Dodgers NOT to start Kershaw.
"the Dodgers have thrown Kershaw in games one and four of the division series three straight years, bringing him back on three days rest each time."
"while today’s game is obviously critical, the fact remains that the Dodgers have to win their next two games or their season ends. Maximizing your chances of winning today, while hurting your chances of winning on Thursday, could actually lower the team’s chances of advancing to the NLCS, which should be the goal the Dodgers are focused on. Instead of looking at only what improves their odds of winning today, the Dodgers should be asking what gives them the best chance of winning their next two games.
"Starting Kershaw today means you can’t start him in Thursday’s game five, when he would be pitching on full rest. In any scenario where the Dodgers advance, Kershaw will pitch one game, so the team’s decision involves whether they want a short-rest Kershaw or a full-rest Kershaw pitching one of the two games. While Kershaw has pitched well in these scenarios before, the reality remains that history shows that pitchers are less effective on short rest than they are on full rest."
They add that if Kershaw goes today, Rich Hill will ALSO have to pitch on short rest for Game 5, since the Dodgers don't have Greinke anymore. And basically, full rest Kershaw + full rest Urias > short rest Kershaw + short rest Hill.
http://www.fangraphs.com/blogs/the-dodgers-should-start-julio-urias/BTW, in those three short rest NLDS game 4s, Kershaw has a 1.98 ERA.