SARASOTA, Fla. -- The best documentation of Zach Britton's historic 2016 season came from Britton himself. He kept a journal with him all year, taking diligent notes about how he felt on a particular day, who he faced, what worked and what didn't, how he recovered from his outings and, well, yes, there is that empty page from the American League Wild Card Game, but enough about that.
The point is, the log is now a resource Britton can rely upon as he tries to repeat his pristine ERA and keep his saves streak intact.
"I can look back on it through the season," Britton said. "Maybe if you're not feeling great, you can look back at similar situations and say, 'OK, that's how I got out of that funk' or 'This is how I stayed consistent.'"
"Consistent" is an understatement when it comes to Britton's 2016 season. He saved 47 games in 47 tries, finishing 63 games overall. Britton set a Major League record with 43 straight scoreless appearances and allowed just four earned runs in all -- posting the lowest single-season ERA (0.54) with at least 50 innings pitched in history.
You'd think Britton would feel pretty good about a year like that, and he does. But beyond the obvious issue that was his absence from the AL Wild Card Game, there's one element of this splendid season -- one specific matchup -- that still bothers him.
So, Zach, what does your book say about Mookie Betts?
"That he hit three fly balls off me," Britton says bitterly.
Britton's season was so unusually awesome that it's interesting to point out one of the very few things that didn't work out. Betts was the one matchup that befuddled Britton, so that matchup is now a motivating factor for a top reliever who never settles.

Britton gave up 31 fly balls last year. That's it -- 31. And Betts hit three of them in his only three plate appearances against Britton.
Granted, only one of those three fly balls was consequential. Betts took Britton deep a week into the season -- a leadoff shot that was the only homer Britton allowed in 2016. It cut into, but did not erase, the Orioles' ninth-inning lead in a 9-7 win. The other two were harmless flyouts in September.
But the mere act of elevating off Britton, with that nasty left-handed sinker, is a feat in and of itself. The 29-year-old is modest about the history he made last season, but even he had to admit he is sometimes surprised when a fly ball occurs on his watch.
"Every now and then," Britton said, "when it hasn't happened in a while, I'll look up and go, 'Where'd the ball go?'"
That happened with Betts' home run -- a moment that stuck with Britton throughout his otherwise fantastic year.
"I let him know how I felt at the All-Star Game last year," Britton said. "I told him, 'There's something about you.'"
What is it?
"I don't know," Betts said. "Maybe he's just made a couple pitches to me that I was able to get up in the air. But he's tough. He has the numbers to back everything up."

Britton put up insane numbers last season, and, as a result, sits just 35 consecutive saves shy of Eric Gagne's all-time record of 84. But the Betts example -- outlier though it may be -- is a reminder of the importance of execution in every instance.
"There were a couple things I tried to do against him last year that I won't do anymore," Britton said. "He was a different hitter last year than he was in '15. I think a lot of it is on me to recognize that he was a young kid, and now he's figured out who he is."
Betts is proof that even when Britton was "perfect," he wasn't perfect. So he doesn't view 2016 season as a standard he has to keep up with.
"I think the best approach is to turn the page on it," Britton said. "You take the good parts of it and the things you learned, and then you focus on this year. Because every year is different. Hitters make adjustments and you have to make adjustments based on how you feel."
So Britton, who battled what appears to be merely minor side soreness early in camp, will just emphasize the execution as he ventures into what he hopes is another historic year. He's got his book to help him on the journey, its lessons emanating not just from the many matchups that went in his favor last year but also the one that didn't.