Chemistry, to most people, is the science of matter. How molecules, atoms, etc react and interact with each other. In wrestling its pretty much the same thing except there is no science to it. In chemistry if you take part "A" and mix it with part "B" then it creates part "C". In Wrestling if you take part "A" and mix it with part "B" sometimes you get part "C" but sometimes you get shit!
You never know, for sure, who is going to mesh well with who. Just because you have two great workers doesn't mean you have a for sure 5 Star match(Rating system is a trademark of RRO News and Brian Tramel and may not be reproduced without the express written consent of RRO). Same goes for two not so great workers. I've seen two guys that really didn't have much going for them but for some reason they gelled really well together. Its a crap shoot, its the world letting us know that there are no guarentees in life.
Prime example, I saw vs Mr.Perfect! How could that possibly be bad? They just didn't get in a good groove and Shawn even mentions it in his book. Motley Cruz is a guy that I have alot of respect for inside the ring. When I was TLCW champion we got a chance to work one another for the first time in a long time. We had high expectations but when we got to the match we both were waiting for the other to call the match or take the lead and it ended up being a very bland match.
Maybe wrestling isn't as complex as advance chemistry but it isn't kindergarden stuff either. There really isn't a substitute for good chemistry in wrestling. Rock/Austin, Flair/Sting.. the list goes on and on. Because its not the moves that we remember but the feeling we get from those who have immeasurable chemistry. So don't watch for that forgettable high spot but rather that unforgettable feeling this business can produce on any given night.