Image Courtesy of Bakhand
Errors in the Combat Log
The above screenshot does not make much sense. How does a player with Improved Shield Block not block a second attack before the buff is lost? How does he or she take a Crushing Blow? Isn't this impossible.
Yes, it is impossible.
This clarifies one of the biggest hurdles for theorycrafters in the game -- the Combat Log is often wrong.
More specifically, the timing and sequence of the Combat Log is wrong. The information is absolutely correct. The combat log is notoriously inaccurate when it comes to posting or sequencing actions.
In the above screenshot, the second Shield Block charge is eaten up 1 second later (at the 41 second marker). Even though the Crushing and buff loss appear to occur before it, in reality both Shield Blocks would have occurred in proper time, then the buff would have been lost, then the string of Crushings would have begun.
I am not the best to describe the mechanics or reasoning behind this; there are others who have parsed the parsing, so to speak, and can give the technicalities.
Recording your own Combat Log
This is something most players are not aware of. You do not have to download a mod to get extremely detailed logs. Just type /combatlog while in-game, then type it again to shut it off. This records to your World of Warcraft game directory.
Be sure you don't run this unnecessarily. For being just a text file, you'll find it grows extremely big extremely fast, especially when dealing with raid situations where it is recording all raid members as well. It can slow down even the best computers to try to open larger Combat Logs with a text editor.
Parsing the Combat Log
Several ways to do this. The two best would be Combat Monitor (Satrina) and WWS. I will provide links as soon as I can.
Alternatively, if you know what you are looking for, go to the time and encounter in your combat log. Use "CTRL+F" to look up specific information (for instance, Dodge). Organize the data however you like.
The method is very basic, but I'm not a particularly computer oriented guy. Using that method of just adding times together was how I determined the attack speed bonus on Parry.