uestion - How do I know if I've 'officially stalled' and need to reset?
The following serves as an example. The #s are not exact, but they ARE representative, so if the weight change differences seem to describe you, then it applies to you, even if the exact poundages are different.
This assumes the average 150-200 lb teenage male. Make adjustments if you are older, smaller, or female.
Here is how training progression might look from week to week, assuming rest/recovery is ideal. When I say "bar speed", I'm making reference to your speed of movement in the concentric portion, i.e. are you really struggling and barely getting that last rep (bar speed very slow) or are you making that last rep nice and solid (bar speed good)
Squat:
135 x 5/5/5 (bar speed good)
145 x 5/5/5 (bar speed good)
155 x 5/5/5 (bar speed good)
165 x 5/5/5 (bar speed very slow)
175 x 5/4/4 (bar speed slow) - note missed reps workout after "bar speed very slow"
180 x 5/5/5 (bar speed good) - note 5lb jump = no missed reps + good bar speed, therefore, try a 10-lb jump again
190 x 5/5/5 (bar speed very slow)
195 x 5/5/5 (bar speed good) - note slow bar speed = 5lb jump = no missed reps + good bar speed
200 x 5/5/5 (bar speed slow)
205 x 5/4/4 (bar speed slow) - note attempt to correct bar speed and missed reps by very small incremental jump
207.5 x 5/4/4 (bar speed slow) - missed reps, small jump, bar speed slow
210 x 5/4/3 (bar speed very slow) - more missed reps, very small jump, very slow bar speed, keep weight the same
210 x 5/3/3 (bar speed very slow) - again, missed reps with NO boost in weight used, attempt one more time
210 x 4/4/3 - time for a reset