Ok, I ran some numbers, 'back of the napkin calculations' so to speak, on how Lindy Coached teams have done in each period.
For his coaching CAREER (1165 games as head coach), his teams goal differential by period is:
1st: +59 (+4.15 per 82 games)
2nd: +51 (+3.59 per 82 games)
3rd: +69 (+4.85 per 82 games)
And those are totals, again, over 1165 games. I think it would be harder to find stats that close over that many games. Basically, his teams, at least in terms of goal differential, are pretty much the same each period.
For comparison, the Sabres this past season over 82 games were:
1st: -30
2nd: +7
3rd: +25