I'm in my early 50's. I never saw Frank Boucher, Bill Cook, Andy Bathgate play who are in Brooksie's top 10 so I have no idea other than looking at their stats like the rest of us how good they really were...I just don't. i'm sure they were great but I just don't know seeing their stats other than Bathgate's don't really raise any eyebrows at least for me they don't. I know they were very responsible for Cups won but I just don't know seeing I never saw them play and I don't recall many hockey historians saying how great they were like they do about guys like Maurice Richard, Jean Beliveau, Eddie Shore, Toe Blake....etc etc and others of those ilk I never saw play but who are revered in hockey lore. That's why this is so tough to do...these kinds of rankings seeing it really is all subjective.
For sure not seeing guys play makes things incredibly difficult. We did a painstaking ranking here a few years back of all-time NYR's by position and I still have my research on Frank Boucher. Important to keep in mind is that I'd watched footage from back then and, as best my memory serves me, defenseman did not leave the defensive zone and you could not pass in the neutral zone. So you basically had to skate the puck up and 3 forwards had to beat 5 defenders. Also only 1 assist per goal in the early days. Not easy to score points. So when you see a guy like Boucher notch 62 pts in 42 games in 1929-30, it is a huge deal and you grasp why his adjusted numbers for that season are 42-118-160.
Keeping point scoring difficulties of that era in mind, let's look at Boucher's killer performance for the Rangers first Cup win. Best of 5 series, NYR vs Mtl Maroons. Circus at MSG, all games in Mtl at the Forum (no bueno). Clint Benedict shutout in game 1, Mtl wins 2-0. Game 2 tied 1-1 end of regulation, Boucher delivers the winner in OT. Game 3, Benedict with another 2-0 shutout, Rangers have to win the next two. Game 4, Rangers win 1-0, Boucher with the lone goal. Rangers win game 5, 2-1, Boucher with both goals, NYR are Stanley Cup champions. Boucher delivered hard core, scoring all but one of the NYR goals in the series... against an excellent opponent who iced 5 Hall of Famers.
I'd also found a good article on Gretzky back then, on why he was the Great One, which did a nice job attempting to compare him to players across different eras. It said: "When counting adjusted goals, Gretzky falls to third all-time behind Gordie Howe and Jaromir Jagr. When looking at adjusted points, his four 200-point seasons adjust down to 170, 166, 163, 156 — still great but no longer singular totals. When looking at these advanced numbers, Gretzky finds himself on the same stage as Howie Morenz and Mario Lemieux and Frank Boucher." Adjusted stats are far from gospel, obviously, but this still speaks to what a great player Boucher was in historical context.
Boucher joined the Rangers at age 25, and here are his first five NYR seasons of adjusted scoring from Hockey Reference:
23-94-117
46-81-127
26-119-145
42-118-160
24-81-127
His career adjusted numbers at Hockey Reference are 1155 pts in 557 games, over 2 pts per game. Again, adjusted numbers are adjusted numbers, but they're perhaps the best we've got to compare different eras. There's obviously no viable way to compare eras. Especially that far back. But when you start to dig, you find a lot of things that indicate what a phenomenal player Frank Boucher was in the annals of hockey history.
Announcer Foster Hewitt, who I believe was calling Leafs' games when Boucher played and for 40 years did play-by-play for HNIC, made these comments while he was calling the '72 Summit Series: "The way the Russians play reminds me of the old Rangers, especially the line of Boucher and the Cooks. They were even better than the Russians. When Frank, Bill and Bunny were on the ice, it always seemed to me they had the puck on the string." An opinion, but an opinion from someone who actually saw Boucher play.
Lastly, from the Hockey Hall of Fame: "Boucher was inserted between the Cook brothers during the Rangers' inaugural NHL season in 1926-27. The unit jelled and exhibited an advanced level of play that surpassed all expectations. The Bread Line developed into one of the most formidable combinations in NHL history. They were such a perfect fit that New York coach Lester Patrick allowed them to devise plays at one end of the rink while the remainder of the team practiced down at the other." Crazy concept, but it seemed to work: they are commonly regarded as one of the best lines in NHL history.