Here is a chronicle of the way that teams' fortunes changed when Sprague Cleghorn changed teams.
I have left out the Montreal Wanderers, as their arena burned down after Cleghorn left and they did not play a full season. (Did Cleghorn have an alibi for the night of the fire?)
Year | Team | With or Without? | Win% | GF | GA | GF+ | GA+
1917-18 | Ottawa | Without Cleghorn | 0.409 | 102 | 114 | 0.98 | 1.09
1918-19 | Ottawa | With Cleghorn | 0.667 | 71 | 54 | 0.95 | 0.72
Year | Team | With or Without? | Win% | GF | GA | GF+ | GA+
1919-20 | Ottawa | With Cleghorn | 0.792 | 121 | 64 | 1.05 | 0.56
1920-21 | Ottawa | Without Cleghorn | 0.583 | 97 | 75 | 0.96 | 0.74
Year | Team | Cleghorn? | Win% | GF | GA | GF+ | GA+
1919-20 | Ottawa | With Cleghorn | 0.792 | 121 | 64 | 1.05 | 0.56
1920-21 | Ottawa | Without Cleghorn | 0.583 | 97 | 75 | 0.96 | 0.74
Year | Team | With or Without? | Win% | GF | GA | GF+ | GA+
1919-20 | Toronto | Without Cleghorn | 0.500 | 119 | 106 | 1.03 | 0.92
1920-21 | Toronto | With Cleghorn | 0.625 | 105 | 100 | 1.03 | 0.99
Year | Team | With or Without? | Win% | GF | GA | GF+ | GA+
1920-21 | Toronto | With Cleghorn | 0.625 | 105 | 100 | 1.03 | 0.99
1921-22 | Toronto | Without Cleghorn | 0.563 | 98 | 97 | 1.03 | 1.02
Year | Team | With or Without? | Win% | GF | GA | GF+ | GA+
1920-21 | Montreal | Without Cleghorn | 0.542 | 112 | 99 | 1.10 | 0.98
1921-22 | Montreal | With Cleghorn | 0.521 | 88 | 94 | 0.93 | 0.99
Year | Team | With or Without? | Win% | GF | GA | GF+ | GA+
1924-25 | Montreal | With Cleghorn | 0.600 | 93 | 56 | 1.24 | 0.75
1925-26 | Montreal | Without Cleghorn | 0.319 | 79 | 108 | 0.95 | 1.30
Year | Team | With or Without? | Win% | GF | GA | GF+ | GA+
1924-25 | Boston | Without Cleghorn | 0.200 | 49 | 119 | 0.65 | 1.59
1925-26 | Boston | With Cleghorn | 0.528 | 92 | 85 | 1.11 | 1.02
Year | Team | With or Without? | Win% | GF | GA | GF+ | GA+
Total | Total | With Cleghorn | 0.614 | 675 | 553 | 1.05 | 0.86
Total | Total | Without Cleghorn | 0.429 | 656 | 718 | 0.97 | 1.06
Teams almost invariably improved when Cleghorn arrived and declined when he left. Especially on the defensive side, where the pre/post Cleghorn squads were 6% worse than league average, as compared to 14% better than league average with Cleghorn. The offensive difference was also positive - 5% above league average with Cleghorn, and 3% below league average without him.
This analysis doesn't take into account the fact that Cleghorn only played the second part of the 1920-21 regular season for Toronto. Looking within that season, and splitting it up by first half and second half:
Year | Team | With or Without? | W | L | Win% | GF | GA | GF/G | GA/G
1920-21 | Toronto | Without Cleghorn | 5 | 5 | 0.500 | 39 | 47 | 3.90 | 4.70
1920-21 | Toronto | With Cleghorn | 10 | 4 | 0.714 | 66 | 53 | 4.71 | 3.79
Once again, Cleghorn had a large impact on his team's fortunes.
Again, you could compare him to Chris Pronger...he moved around a bit but he transformed every team he played on.