I scout for it identify it is coming or if I don't get a good scout I keep extra attention to the mini map during the usual timings WM drops tend to hit.
Regardless of this I'm struggling with turtling Terrans who just send in one medivac after the other, and the ones who get drilling claws I find it extremely hard to defend perfectly.
I tried adding cannons when I identified drilling claws drop, in addition to this my pref opening is blink stalker with hallucination scout to be even more prepared but the speed at which they burrow cannons are basically useless unless he flies straight into my cannons and doesn't unload the WMs which they identify with scanning or previously failed drops anyway.
I tried watching pro matches and I've seen they deal with it perfectly but just as often I see even pro gamers unable to spot this if they just happen to have their attention elsewhere.
Maybe it's just me but I find it very unfair that Terrans and Zergs can basicly delete an entire mineral line of probes where you have 2 second reaction time.
Basicly you are playing a game and you spot the drop 2 late and the game is over in less then 2 seconds. I really dont know what to say.
The amount of times I've just played a game and within 2 seconds I find myself typing gg because I know I will never hold the followup 2 base all inn with half the worker count of my opponent. Why can't Protoss get a unit that deletes a mineral line in 2 seconds and wins you the game like Zerg and Terran does? QQ Protoss tears.
Any tips on how to deflect these drops, better minimap awareness is not gonna help even pro's mess up half the time.