Interesting Questions Raised
Tim Horton was a bit before my time, and I didn't really get to see him in his prime. Why is he so highly regarded, at least to the point of being considered better than Pronger? I am not arguing for either player, I just want to make my point and hopefully someone can tell me more about Horton.
Horton never really came close to winning the Norris. I mean, yeah, he finished as runner-up twice, but both times, it was by a very wide margin behind the winner. It's not like his competition for the Norris, during his prime, was that spectacular, either. Norris voting records don't seem to indicate him being recognized during the Doug Harvey era, and his peak, at least in terms of Norris voting, happened in between the Harvey era and the Orr era.
I just have trouble comprehending Horton being better than Chris Pronger. The latter has a collection of accolades that is just spectacular. Hart, Norris, 2 Olympic Golds, Stanley Cup, easily could have 2 Conn Smythe Trophies and should have at least 1, but was bypassed due to his dirty (and terribly dominant) play. Pronger's Norris voting record is better, and has been accomplished against better competition.
I really just don't know much about Horton, and if he really was better than Pronger, I really hope someone explains to me why. Horton does have one more first-all star team berth, but Pronger has faced tougher competition for that first-team defense pairing.
You raise a number of interesting questions which I will try to answer in the context of the respective eras.
Achievements.
Horton being a member of four Stanley Cup teams is a very strong point. Stanley Cup wins with a good chance of 1 retro Conn Smythe are very telling. Possibility of winning Olympic gold did not exist.
Pronger - achievements have a certain randomness to them. The standout season from time to time but no stretch of sustained championship level play. He may have had a slightly larger pool of competing defensemen for the first all star team BUT no one from the pool faced the same high level of forwards game after game.
Context of each era.
The Norris voting in Horton's era has to be analyzed within a context. In the O6 part of Horton's career, each team had at least one if not two HHOF caliber defensemen virtually every season. Boston in the mid sixties being the exception for a couple of seasons. Also each team had at least 1 or 2 HHOF caliber forwards, some as many as six.
During Chris Pronger's career, at any given time, he may have been playing against 6-8 HHOF caliber defensemen, effectively at least 20 of the teams would not have HHOF caliber defensemen. Likewise very few teams have any HHOF caliber forwards, let alone multiples stretching to six.
Comparing the two during the regular season leads to an obvious question. During how many shift was each defenseman seriously put to the test. Horton playing against Montreal would see the Beliveau and Richard Line two out of every three shifts, supported by quality HHOF defensemen at least half the time. Same thing against Chicago - Mikita and Hull line two out of three shifts supported by Pierre Pilote. Detroit with the Howe and Ullman line supported by two HHOF d-men. Even the non-playoff teams had one solid line supported by a HHOF caliber defenseman. Horton was put to the test at least 1/2 of each game, mostly 2/3 of each game by quality opponents. On the other hand Chris Pronger has many games where he is rarely tested by HHOF quality opposition.
In the playoffs this is most noticeable. Look at Pronger this year. New Jersey - Kovalchuk playing without an elite HHOF center or defenseman mananged 1.2PPG against the Flyers and Pronger. The Bruins would have eliminated the Flyers with an average NHL coach.
Pronger certainly did not look too physical against Lucic - not a Gordie Howe, Bobby Hull or Jean Beliveau caliber player. Against the Canadiens. Two good games against an offensively weak team then a bit of a turnaround tonight.
Physicality.
I'll throw in Scott Stevens because someone added his name. It is much easier for a defenseman to be physical today because the forwards leave themselves vulnerable and the defensemen are not very supportive - suicide passes or bad passes into a players skates,etc. A hitting defenseman just waits and crashes into the vulnerable player.
Also you have video analysis. Today's defenseman can scout tendancies and plan hits. Video was not a factor in Horton's era.
Horton did not have the advantage of playing in an era when defensemen made their own forwards vulnerable with bad passing so you could get a dissuasive hit early. Part of his game would be physically defending territory against the likes of Gordie Howe, Bobby Hull and Jean Beliveau. Two seven game series against in one playoff against first Montreal then Detroit was very demanding physically. Today such match-ups are few and far between.