The Boston Celtics say hi.
The Yankees have been in existence since 1903, which is 110 years. they have 27 championships, which is 24.5% of their leagues' championships.
The Celtics formed in 1946 which is 66 years ago and have won 17 championships 25.8%.
The Montreal Canadiens have been in existence since 1909 and have 24 Stanley Cups, which is only 23.1%, but they operate at a disadvantage under the Canadian dollar which is worth less than the American Dollar.
Secondly, the rules are different today than they were in 1993, 1970, 1940, 1927, and 1903.
Ownership? How did the Yankees do under the watchful stewardship of the Columbia Broadcasting System?
Value? The Yankees are valued at over $1.5 Billion, but that is not a real number. It's on paper, determined by finance guys and accountants pouring over balance sheets. Would the Yanks fetch the $2.1 Billion that the Dodgers just actually sold for in 2012? Perhaps, but who knows until they are actually put up for sale, which is probably not happening in my lifetime.
Recent performance? 1 World Series title in the last 5 years. 1 World Series Title in the last 10 years. 1 World Series title in the last 13 years. Here's the thing...it's the same title. (Disclaimer: Won in 96 and 98-00, widely believed to be no thanks to their owner and managing partner who was banned from day to day management when the foundation of those teams were developed.)
Operations? Six years ago, the Yankees signed a 32 year old to a 10 year contract guaranteeing him $275 million...and are now trying desperately trying to find a loophole to get out of it (Where have you gone Howie Spira? Our Empire turns it's lonely eyes to you. whoo, whoo, whoo.). The Yankees' farm system has taken a huge hit over the years for signing Grade A free agents as prior to the current CBA, they gave up draft picks for the privilege of signing said FAs.
The Yankees have some talent in their lower farm system, but AA is the weed out level. Most personnel in the know (including their own) will tell you that the AA and AAA levels are lacking.
Bottom line...It's pretty arguable...
Again this is not about the Yankees.