randomization mistake

[mickeyi]

yes this is correct. either all of cong first or all of incong first, as long as they stay together within.

[jarvis24]

I think one constraint on BGR applications is that there can not be a break in the set of items sharing the same BGR value. The few trials that break the BGR blocks may be what's causing the problem here. Can you add them to the blocks using the corresponding BGR values?