Jelena Ostapenko (LAT) vs. Timea Bacsinszky (SUI) . Amazingly, this semifinal is being played on the birthday of both players: Ostapenko is turning 20 while Bacsinszky is turning 28. Ostapenko is playing in her very first major semifinal, having extended her winning streak to 4-0 against Caroline Wozniacki in the quarterfinal, while Bacsinszky is plying in her second, after dispatching the French crowd's favorite player, Kiki Mladenovic in straight sets in their quarterfinal. The two have never met before so this will be a new experience for both players. On one hand, Ostapenko is so young that the significance of her accomplishment has probably not sunk in yet. This is the blessing of youth, but it usually does not last for the entire duration of the match. For Bacsinszky, she has been here before (in the 2015 Roland Garros semifinal) and will most likely use that experience and her superior movement to outlast her hard-hitting opponent. After all, Bacsinszky has already showed that her superior defense could defeat the offense of Mladenovic and Venus Williams already in this year's tournament and will almost certainly repeat this performance to reach her first major final. PREDICTION: Bacsinszky.
Karolina Pliskova (CZE)  vs. Simona Halep (ROU) . I still believe the most important match in the draw was the showdown between Elina Svitolina and Simona Halep in the quarterfinal. Obviously Halep ended up winning it, but it was an incredibly tense and thrilling affair. Svitolina quite simply outhit Halep for nearly 2 sets. She wracked up huge leads in both sets, going up 5-1 in both of them. In the first one she ended up winning 6-3, but in the second she ended up losing 5 games in a row to go down 5-6. Then, Svitolina survived 4 set points on her serve (starting at 0-40) to force a tiebreak where she earned a match point at 6-5 but lost that point and 2 others in a row to lose the 2nd set. The Ukrainian then completely "lost the plot" and failed to win a game in a 20 minute bagel set. Karolina Pliskova dispatched the other French hope Carolina Garcia relatively easily and is now just one win away from being ranked #1 on the WTA tour. Sadly, it is very doubtful that Pliskova will reach #1 this week, because Halep has a 4-1 head-to-head record against Pliskova. If Halep could survive the barrage of Svitolina, she should have little difficulty outlasting Pliskova's offense to reach her second major final at Roland Garros in four years. PREDICTION: Halep.