Ah, my bad. 'bi' is one of those prefixes for monthly that can either mean "twice a month" or "every two months". Anyway, I use the shortest time period available. Sorry for the confusion.
I typically like to see 200-400 PA before I'm satisfied that a player is being productive:
https://www.fangraphs.com/library/pr...s/sample-size/
Agree with you on catcher value; based on the way they're usually generated, I'm looking for a guy who can manage the staff, hit over 0.225, and have an OPS near league average. Typical catchers hit for low average with comparatively high power. If they have some eye, it's a real bonus.
I play my backup every 4th game anyway, so what's the point of overpaying for a guy that's only playing 120 games a season? The one exception for me, is I had a switch-hitting catcher who could hit .300 with 20-30 homers per year. I kept that guy a little while because the payroll was available.
edit: To fill in the details a little bit, I look at it like this. Every player has these 2 things: an adaptability rating that controls how quickly they settle into a new situation, and a scouting report with some accuracy attached to it. So in the good/bad performance scenarios, after 400 PA, I look at it like this:
first 400 PA in a league, good performance, high scout ratings:
Player is likely pretty adaptable. High scout rating more likely to be accurate. It could still be a fluke, but 400 PA is a pretty good sample size for hitters.
first 400 PA in a league, poor performance, high scout ratings:
player may not be adaptable, or high scout ratings are wrong. Needs more time before I look at them seriously. Could still be a fluke.
I generally don't pay a ton of attention to players with low scout ratings. But with a couple hundred more PA, you can see if the performance is coming up (player is settling in, reverting to mean perhaps) or really not coming up (player is overrated, or development has been stifled by advancing too quickly, etc.)
That's just my thought process.