Last time I began to play often to plat/diamond/master players... Not too often, but still I saw a lot (especially on 4 players maps, in both ladder and custom games) that Protoss players do VERY early expansion. I would name it "1-pylon" expansion. Idea is following: build 1st pylon and once have enough money - build nexus on natural, after that - continue usual build.
If not scouted and managed in time - he will win (just because has 1.5 better economy). If scouted - at least for me - it is hard to manage. I didn't expect such kind of audacity: last few month of play I saw Protoss players do either 1-gate-gas-core, or 1-gate-gate-gas-core. For any of this case you could delay scouting a little.
I have ALMOST deny that, but failed due to mistakes in micro. Still, that was very doable...
For terran players: in my experience, 2 rax expand is very powerful strategy, but I found out that players do 1 rax expand!!! and still fill comfortable... still risky, in my opinion: if you scout that in time and don't expand your self but invest in army - you will be able to kill him in 8-9 minutes...
Question1: how viable is this strategy of NO-ARMY expand
Question2: how to apply this strategy on practice for a) Protoss, b) Terran. As Terran you can wall-in, but for Protoss, how to prevent scouting?
Question3: Probably the reason why opponent decided to do a no-army FE is/was opponent confidence in own skills (in such kind of matches my opponent was slightly favored) and he tried this cheese strategies just for fun?
Thanks, any thoughts are welcome!