Robert Joyner underscores some key features about the fight:
A straight sell on the sporting aspects of MMA can vary greatly. Match two of the top 5 pound 4 pound guys on the planet like BJ Penn and Georges St Pierre, and you can do huge numbers like UFC 94 has purported to do. On the other hand throw together two guys also in most folks Top 10 p4p at the time they fought, Dan Henderson and Anderson Silva, and the numbers fall somewhat flat. Conversely, some of the bigger box offices on PPV have had little in the way of sporting impact (Shamrock vs Otiz 2, Hughes vs Gracie).
The month of April will give a contrast of sorts for the two booking options available, sport vs entertainment. Anderson Silva vs. Thales Leites will take place and will do serviceable numbers based on the UFC brand. It will feature the unquestioned best 185 lber in the world, but from a perspective of a fight that gets the juices flowing, the fight that I will be looking most forward to that month will be Frank vs Nick. One would have a hard job making a case that Frank Shamorck is a top ten fighter at 185 anymore, but his fights with Phil Baroni and Cung Le over the past two years have been a couple of the more entertaining fights that have taken place. The build to these fights were almost as much fun as the fights themselves, the Baroni fight especially. A fight like Diaz vs Shamrock is almost as much about the sizzle as it is about the steak. The “MMA purist” may scoff at the fight but this is a guilty pleasure that will be well worth indulging.
My only tweak would be that the notion the purist in MMA isn't in favor of this is somewhat overplayed. Certainly no hardliners are going to accept the idea this match means a great deal for MMA or even for either fighter (although some can be gleaned there), but that the entertainment factor in the fight - combined with the engaging personalities, back story of rivals clashing - as well as the genuine unpredictability in the outcome has everyone's attention. Certainly there's some unpredictability in Bob Sapp fights, but the legitimacy of skills involved with the two fighters mostly removes that circus element. And because this fight is at a catch weight without any title implications, there is no attempt by Strikeforce to impose any overt seriousness about the content. I tend to think Shamrock should win, but the truth is there is some mystery about how this will play out that makes watching the fight imperative. This is not tournament MMA to crown a champion, but is most certainly a perfect example of "creating fights people want to see".
And at the end of the day, what true fan of MMA doesn't care for grudge match?