The obvious team strength was ripped last year. They went from worthy warriors to the Spartan guys from 300 or something. Instead of 6 packs, they had 10 packs. They were good. Really good.
Greg "Dirty South" Holland - The 9th inning is mine
Holland picked up almost where he left off last year. Holland struck out 3 out of every 8 batters, and that was a decline from last year! Holland walked only 8.3% of batters, which rose from last year. That's an unfortunate confluence of factors, but Holland's declining from a precipitous high. Of course he was going to decline, if only because the peak he was on was so thin that no one can stand on it very long. Holland was still worth 2.3 fWAR this year, which tied with Andrew Miller for 7th among relievers.
Holland still limited home runs (0.43 HR/9). He still stifled contact (.268 BABIP allowed). He actually got a lot of ground balls (48.1% GB rate), which is very different from last year. He used his slider a little bit more than last year, and his slider gets more ground balls than his fastball. The heat maps below show that Holland maybe tried to keep the ball down a little bit more this year compared to last year. I wouldn't argue with you if you said the two images below were not really much different.
2013 Heat Map (Baseball Savant; catcher's perspective)
2014 Heat Map
During the postseason, Holland gave up only 1 run, which was during the final inning of Game 1 of the ALCS. His Wild Card outing was rocky (he had 3 walks), but he managed not to let any of those guys score.
Grade: A
Wade "The Trade" Davis - There is no 8th inning
Davis ranked 2nd in reliever fWAR behind Dellin Betances, who threw 90 innings. On a fWAR per inning basis, only Aroldis Chapman was a better reliever. Davis, however, had a lower home run total than his ERA. His ERA was 1, if you remember. Going down the reliever leaderboard on FanGraphs, the next name who gave up 0 home runs is the next guy on this season in review.
Davis does inhuman things with a baseball. There are gifs in the comments. Watch them, and then cackle in glee with Josh Duggan as opposing hitters are rendered as useless as a fluffy bunny swinging a baseball bat.
Grade: A+
Kelvin "Kelvy" Herrera - The beginning of the end
The initial H of the HDH trio. He gets the party started, if you can call the total elimination of opposing hitters a party. Herrera himself had a decent season of an ERA roughly equal to his fWAR: 1.4. The story is that the Royals' trio didn't give up many runs. I do enjoy a good non-fiction story.
Herrera is the only one whose really primed for some unfortunate regression. Like Davis, Herrera did not give up a home run. Unlike Davis, Herrera didn't strike out almost 40% of all batters. He struck out about 20% of all batters. Unfortunately, Herrera doesn't have the same control the other guys do, and he walked more guys. All that adds up to a 3.50 xFIP, which is far higher than Davis' and Holland's. It was, regardless, an excellent season.
Grade: B+
Aaron "Marlin" Crow - The 6th inning was his inning
This whole thing didn't really work out. Crow had a miserable season in which he accrued negative value. Near the end, I basically expected him to give up a home run every time he came to the mound. The Royals obviously were not enamored with him, since they acquired Jason Frasor mid-season and didn't put Crow on the postseason roster.
Grade: F
Jason "New Guy" Frasor - The 6th inning is now his inning
Mid-season acquisition Frasor came in and performed admirably in his limited innings. He was a member of the under-2 ERA club in his 17.1 innings with the Royals, but his peripherals were maybe a bit better than Herrera's.
Grade: A-
Brandon "Ice Man" Finnegan - The 6th inning is now his inning
I'm losing track of who owns the 6th inning. Whatever. Finnegan threw only 7 innings in the regular season. They were great innings, but there's not much to say there. It was that Wild Card game performance that really cemented his reputation as a guy with ice in his veins. He was charged with 5 runs in Game 4 of the World Series, though. He's still young and must learn.
Grade: B+
Louis "Doesn't own an inning" Coleman - The ROOGY, I guess?
Coleman had a great 2013 in his limited time, but he could not harness whatever it was he had. He gave up a lot of home runs, his strikeout rate cratered, and his walk rate did the opposite of cratering.
Grade: F
Francisley "Doesn't own an inning either" Bueno - The LOOGY, I guess?
Bueno had 0.0 fWAR. He was a replacement level reliever, and he was often replaced by Scott Downs and Tim Collins. So there you go.
Grade: D
The other guys
Michael Mariot: F
Tim Collins: F
Scott Downs: F (walked more than he struck out)
Casey Coleman: F
There's really no point in grading anyone else due to a lack of innings. Even the guys listed above perhaps don't need grades due to their small sample sizes, but they had double digit innings instead of single digit innings. The bullpen lacked depth beyond the top guys, but they luckily had so many top guys that it didn't hurt the team very much.