So since points have once again begun dropping, we're going to see volatility in the rankings we haven't seen in a while. Djokovic is less than 2300 points in the lead right now.

Medvedev is defending max points at Cincinnati, Shanghai, Paris, ATP Finals, and finals at both Canada and the USO. It's unlikely Medvedev can improve his performance there, so he'll be gunning for the #1 position before Canada.

**The coming events from now to then: Dubai/Acapulco, Miami, Monte-Carlo, Barcelona, Madrid, Rome, RG, Halle/Queens, Wimbledon, Hamburg, Olympics, Washington.**

Djokovic is defending Dubai - 500, Miami - 90, MC - 180, Madrid - 1000, Rome - 1000, RG - 720, Wimbledon - 2000. Total: 5590

Medvedev is defending Miami - 90, MC - 360, Barcelona - 300, Madrid - 10, Rome - 10, RG - 10, Wimbledon - 90. Total: 870

Given their schedules, neither is playing Dubai. That makes Djokovic's lead <2050.

Forget about Miami for now.

Djokovic's schedule is MC and Belgrade after that, implying no Barcelona, and more than likely one of Madrid or Rome, not both. Let's say Djokovic wins Rome, losing Monte Carlo in the semi, and wins Serbia. In total, he will come out with 1000+500+360+250 = 2110 points, losing 70 points from before, making his lead <1950.

Now assume Medvedev gets the the QF of everything from MC-Wimbledon. It's optimistic given his previous years, but it's not ridiculous - the man's the world #2, so a QF isn't unexpected. That will give him 1510 points, roughly 400 points from #1.

That doesn't include Miami. If Medvedev wins Miami, that will give him another 400-1000 points to chip away from Djokovic's lead. If Medvedev wins Miami, becoming world #1 is a very real possibility. Even if Djokovic wins Miami and Medvedev loses before the final (+640 for Djokovic), that doesn't entirely stop Medvedev from being a threat. This will be very interesting to see play out in Miami and Monte Carlo.

Obviously the numbers here are very hand-wavy, since there's so many permutations of results right now, but the numbers I laid out are somewhat optimistic for Djokovic and somewhat middle-of-the-road for Medvedev. He can perform better or worse, but it's impossible to tell just yet.

EDIT: Forgot that only half points are being dropped. Adjusted to account for this.