This build is really awesome, even vs grandmasters and it will train your micro with sentries a LOT. It's very classic, I kinda made my own version from platinum to high masters.
9 pylon ( forge fast expand )
14 forge ( safer, and you can attack hatch first )
18 gas x2
23 zealot * You are sending the zealot into his 3rd *
31 stalker * same for the stalker and mothership core *
31 warpgate * you can take a probe to fake a warpgate push *
33 Mothership core * You will kill queen(s) and drones and force lings*
34 pylon ( in your main ) * if no 3rd, forget the allin, you have to stargate *
36 Robo , on your natural, hide it from overlords if possible.
40 add two more gateways
42 take your 2 gas on natural
44 +1 weapon attack
you will need 2 immortals, 1 warp prism, to go, make 7 sentries and stalkers from your 7 gates and try to go through places where forcefields are efficient. The best timing I have ever hitted for my go is 9' but it should be at least 9'20 to be efficient, else his production will catch up on 3 bases. Don't forget to put a pylon when you go to secure from lings runby.
Make sure to have a control group for your sentries. Don't hesitate to warp more sentries during the fight, it's your main unit. if he somehow holds or commits too much holding you can go for 2 robo colossus all in after that push.
Submitted by: NalRa