MArcomage

Interesting concept. How about to make it:

Mode1: discards position which is left of the matching position
Mode2: discards matching position
Mode3: discards position which is right of the matching position

But what's up when it's in the first position? I can still choose mode1?

Well, then we have two options

1 - the matching position is chosen instead
2 - the eight position is chosen (wrap around)

I vote for the first one, it's more ambushlike.