Zombie jump distance in alpha 20

[Yup]

I've noticed in my base defense I left a gap of two horizontal and one vertical blocks between stairs and the walls i'm on, and sometimes zombies can jump over. what's their maximum jump distance?

[Mardoin69]

I believe it's 2 blocks so, if you had a gap (where you could place two full size blocks between) they shouldn't be able to jump all the way across. However, if they're jumping from higher elevation, physics would theoretically allow them to 'just make it' onto that 3rd block possibly. Haven't tested that theory though.
Edit;
The problem comes when there are multiple zombies....they actually climb on each other and if one is 'fell down' they can be extending out over the gap a bit allowing the other zombie to clear the gap. That maybe what you're experiencing. They absolutely do this when it comes to vertical objects. Like building a 2 block tall wall normally keeps them from getting over.....until another zombie is there too. Then they climb over each other. In fact, I've had where they climbed over 3 block tall walls due to multiple zombies they were climbing over each other. So, I always build walls 4 block high...minimum now.

Edit:Edit: Tbf....that could've been a fluke glitch they got over the 3 block high but, I don't chance it. I know they'll get up ladders that I have to jump from an object onto if they dogpile under it.....which is why I always put hatches at top of my ladders.

[Gintarou]

they can jump further im not sure exactly how far bt I have a 4 block wide moat and one just leap the distance