How's your thumb position while slapping?

[Suckbird]

When i first started to slap, a guitar player showed me how to do and you can guess the result..
my thumb was pointing to the floor and i had my hand resting when i was slapping, it looked awful and everytime i slapped i hit all the other strings to with dead notes...

after that i bought the slap bass program and i started to slap more upwards, i see alexi's thumb is pointing straight to the head of the bass but my thumb is pointing between straight upwards and the head, is this bad?

Also, i see people slap with their arms 90degrees, but alexi slaps with a big bow on his arm, is there any proper technique?

[lethifold]

I position my thumb straight down, perpendicular to the strings most of the time. If you practise enough you can hit each of the strings very accurately. But unless you are willing to work at it, position your thumb parallely to the strings ie- pointing directly along the fretboard of the bass

[La Garrida]

Hey, I play at a slight slant downwards. I guess that with any technique its what you're most comfortable with. Wooten tends to hit the string and thump down to the one below. Some would say that that's the perfect slap technique as you can then do more things like double thumb slapping etc. But being realistic I think it should be at the angle you feel is most comfortable when rotating your wrist.
I recommend just playing totally relaxed rather trying to force your hand into a position and seeing what happens. Then if you feel more comfortable playing like that, play like that.

[Bassic83]

Rule #1- Keep the thumb parallel to the strings.
Rule #2- If necessary to implement Rule #1, shorten the strap. Crank that badboy up to yer armpits if you have to.
Rule #3- Strike "through" the string. If you hit it and leave yer thumb on the string, it'll stop the good vibrations. Allow the force of gravity to assist your thumb. You should be hitting near the "top" of the string, with your thumb stopping either in the space between the struck string and the next string (this is striking 'through' the string) or lightly resting on the next string. If you hit so hard that you play dissonant chords, you're putting way too much force to it...
Rule #4- Relax. You'll get more out of your slap technique when you realize it's not how hard you hit the string, but that it's all in the wrist.

That's my technique in a nutshell...

[Martybass]

My thumbs at about 45 degrees to the string I suppose. But then again, im no Mark King...

[Bassic83]

I learned from Mark King... ...and Vernon Porter...