I sort of mastered MC on Vanilla WOW. Needs some explanation I know
I was the guild main tank after we split from an alliance where 2 smaller guilds raided together.
We were taking most of a night to do MC, and it was holding up our BWL progress.
I started pulling faster, not stopping after each trash pack etc but literally rolling through one after the other, the other tanks started getting comfortable and they then started watching far more closely and would get ready for the next trash, as the last were dying the next would be pulled.
When this started the whole raid would virtually be crying about no mana, they were not playing efficiently, not fully using class skills properly to manage mana for high sustained DPS, or high sustained healing, but instead going for max crits etc.
They adapted however and over a couple of months a leisurely MC run that would take 3+ hours with people constantly going for a bio, to make a cuppa etc, ended up at about 1.5 hours of practically non stop pulling.
Next boss duties would be being assigned as trash was being cleared, other than to top up mana, maybe a quick gear switch for players, eg FR gear for tanks. There would be only seconds of downtime between clearing trash and starting a boss.
It wasn't me owning the game, but because of my direction a relatively relaxed guild jumped from about 10th to 4th on the server in a couple of months. It was probably my most fond memories of WOW to be fair. MC speed runs, trying to shave a minute off here and there. It triggered success and that remained till I left that guild probably 2 years later, they carried it on for another expansion or so, but kind of slowed again after that as a lot of the more hardcore players seemed to be leaving WOW.
God knows how it must have felt for new comers going on their first serious raids. I remember my first MC, how big and dangerous it seemed, and as I said it was relaxed back then
It rolled into BWL progress, we went from starting and bombing badly for a month on the first encounter (which was why I was annoyed at the slow MC raids because it limited time to progress) to completing it withing a month or so. Gear was a real issue at the level we played (was 2 nights per week back then, and a lot of rotations so had bad gear dilution). I was writing the strategies based on any snippets I could find on BWL, and talking to one of the tanks from one of the best guilds globally, he wouldn't give it all away but would go far enough to help me if I was saying something that was wrong, or confirming what I suggested would work. Have to bear in mind this was before all the sites that publish detailed strategies existed.