So, I've looked around for a solid bit, and have found absolutely nothing about this. I'm trying to make a treadmill, and when the player reaches the end of that treadmill, it teleports them to the back of it, and adds 1 to the counter. Then, once that counter reaches 15, it gives 20 seconds of speed to the player, so it eventually stacks up. Here is the current skript:
```
on walk over mossy cobblestone slab:
if player's yaw is between 1 and 400:
set {_loc} to the location 2 meters west of the player
teleport player to {_loc}
add 1 to {treadmill.%player%}
if {treadmill.%player%} reaches 15:
execute console command "/effect give %player% speed 1 20"
```
```
on walk over mossy cobblestone slab:
if player's yaw is between 1 and 400:
set {_loc} to the location 2 meters west of the player
teleport player to {_loc}
add 1 to {treadmill.%player%}
if {treadmill.%player%} reaches 15:
execute console command "/effect give %player% speed 1 20"
```