Jon Lester

On May 12, Lester was sporting a 1.16 ERA and 1.11 WHIP. However, it didn't take a Sabermetrics Ph.D. to know dark days lie ahead. Not only were Lester's 90.2% left-on-base rate, 3.62 xFIP and 3.91 SIERA harbingers, his modest 8.3% swinging-strike rate was way out of whack with a near-dominant 24.7% strikeout clip. Sure enough, the regression monster visited the North Side, ballooning Lester's ratios to 5.41 and 1.61 over his final 133 innings. To be fair, it was more than regression; the veteran lefty was also a victim of bad luck with a .360 BABIP and 67.5% left-on-base mark. His swinging strike rate edged up to 9.2% but Lester's strikeout rate predictably dropped to 20.8%. Another red flag is a drop in fastball velocity to its lowest level since 2007. Entering his age-36 season with a ton of mileage on his left wing, Lester is fantasy filler, best utilized in a streaming capacity.

Lester outpitched his peripherals by a huge margin in 2018, leaving what looks like a wide range of possible outcomes this upcoming season. All three of Lester's FIP, xFIP and SIERA were over a full run higher than his 3.32 ERA. The lefty's strikeout and walk rates went in the wrong direction, with his K-BB% falling from 15.7% to just 11.2%. That was the 17th-worst mark among 78 pitchers with at least 150 innings. Meanwhile he continued to allow home runs at an above-average rate as his groundball rate fell dramatically, from 46.2% to 37.7%. His 8.5% swinging-strike rate was a five-year low. Part of the reason for Lester outpitching the estimators was the Cubs' stellar defense, but another part of it was luck. Lester has proven to be one of the most durable arms in baseball, surpassing 180 innings in 11 consecutive seasons, but at 35 years old, his days of frontline-quality performance are fading fast.

Lester validated his reputation as one of baseball’s more durable arms by making 32 starts for the fourth consecutive season in 2017, but he was one of several Cubs to experience a World Series hangover. After submitting no worse than a 3.34 ERA and 1.12 WHIP over the previous three seasons, Lester saw those marks jump to 4.33 and 1.32, respectively, representing his worst showings since 2012. Lester wasn’t a victim of bad luck either, as his walk and home-run rates climbed while he lost a tick of velocity on his fastball and cutter, his primary pitches. Now 34 years old and with no injury cited as the reason behind his demise, Lester may need to get creative with his sequencing to mask his diminishing stuff and retain status as a viable top-of-the-rotation arm. Even if he’s unable to do that, Lester should remain a quality source of counting stats since the lost velocity didn’t prevent him from lifting his swinging-strike rate to 10.9%, the second-highest percentage of his career.

Lester's age-32 season was arguably the best of his 10 at the big league level as he spun career bests in ERA, WHIP, and batting average against (.209). Little changed with his skill set or his approach against opposing hitters, however, as he struck batters out nearly one-quarter of the time (24.8 percent) for the third straight season and kept his walk rate (6.5 percent) a tick below his career rate (7.8 percent). Despite his ongoing refusal to throw over to first base in order to keep baserunners honest, Lester stranded 84.9 percent of the baserunners who reached against him -- a big jump from the 71.8 percent he held in his first season with the Cubs, and a noticeable spike from his career 75.3 percent mark. There is little reason to expect a full repeat of 2016, but Lester should again have plenty of run support, a good defense around him, and a bullpen capable of protecting his leads this season. That's a profile worthy of a fantasy ace, but one drafted toward the bottom of the tier.

The Cubs shelled out big bucks for Lester last offseason and he earned his money with a strong performance in 2015 - except in the win-loss department. With just an 11-12 record atop the Cubs' rotation, Lester was a mild disappointment in leagues that count wins, but with 207 strikeouts, a 3.34 ERA and 1.12 WHIP, he was every bit the ace he was expected to be. That said, Jake Arrieta surpassed Lester with his brilliant second half in 2015, so don't be surprised to see 32-year-old lefty move down to second in the rotation. Lester's 4.4 K/BB last year nearly matched his career-high mark of 4.6 in 2014, but he had only topped 2.8 in that category once before this two-year run. One year is a fluke, but two years is a trend: this looks like the Lester you are going to get. Bid for an ace - he'll get you the wins in 2016.

The A's traded for Lester as part of their push to go all-in for a World Series title last season, but he let A's fans down in the AL Wild Card Game, allowing six runs in 7.1 innings and failing to hold a late four-run lead. After a terrible 2012 (4.83 ERA), Lester has dropped his ERA by more than a full run in consecutive season, putting up a 2.46 ERA in 2014. He got his strikeout rate back up to 9.0 K/9 after it had slipped into the 7.0-range in back-to-back seasons, and his durability continues to increase his value, as he's made at least 30 starts in every season since 2008. Lester became a free agent after his short stint in Oakland, and landed a six-year, $155 million deal in December to head up the Cubs' rotation.

Lester needed to re-establish his bonafides in Boston after the 2012 season when he went 9-14 and had career-lows (as a full-time starter) in ERA, WHIP and H/9. This, after his starring role in the September 2011 collapse. He's not the power pitcher he used to be, but Lester turned in a stellar season that culminated in a 4-1 record and 1.56 ERA over five postseason starts. At age 30, Lester is entering the final year of his current contract as Boston's No. 1 starter. He'll be pitching for the next big contract.

The hangover from 2011 that stayed with the team in 2012 also stayed with Lester, who had a career-high 4.82 ERA and experienced a drop in his strikeout rate for the second straight season. As hitters made more contact, Lester's batting line against and home runs allowed rose to career highs. He is still a workhorse, having thrown more than 200 innings in four of the last five years, and at age 29, time is still on his side. Like every struggling pitcher on Boston's staff, the hope is that the return of former pitching coach John Farrell (as the team's manager) will have a positive impact on Lester.

Lester had another strong season, his fourth straight, and at 28, he's entering his prime years. The left-hander suffered some control issues and saw his strikeout rate drop, but he had stretches of dominance, too. Along with Josh Beckett, Lester is at the top of Boston's rotation and pitches in front of a run-producing lineup. The X-factor entering the 2012 season is how he'll respond to the leaks about his clubhouse behavior that came out of Boston's late-season collapse. As a dogged competitor who never gives in, Lester should be driven to change perceptions.

Lester won a career-high 19 games, threw over 200 innings for the third straight season, and finished fourth in the Cy Young voting in 2010. His 9.7 K/9IP led the American League and he held opponents to a .220 batting average (fourth in AL). Other than a slight uptick in walks, Lester proffered another dominant season as Boston's de facto No. 1 starter. All signs point to another big season from him at age 27 as he continues to be the most consistent of the Red Sox's starting pitchers.

Lester, 26, posted his second consecutive strong season after beating cancer, throwing over 200 innings in 2008 and 2009. Of particular note, Lester improved his strikeout rate from 6.5 K/9IP to 10.0 K/9IP last season. That translates to 73 more punchouts in seven less innings. He's been Boston's most consistent starter during his recent run. The walks, the bugaboo early in his career, are dropping and Lester's clearly becoming one of the better pitchers in the AL.

Lester became Boston's ace in 2008 and was the team's most consistent pitcher from April to October. What changed for Lester is that he began throwing more first-pitch strikes while walking relatively fewer batters. He appeared to be getting stronger as the season wore on, even while pitching 129 innings more than his previous career high. Lester established himself as one of the game's best starters during the second half of the season and will be part of a fine threesome along with Josh Beckett and Daisuke Matsuzaka. Beckett may be the nominal No. 1 starter and Matsuzaka may have had more wins, but Lester was clearly the best on the staff.

Lester, MLB's winner of the Tony Conigliaro award for overcoming adversity, was brought back slowly in 2007 after battling non-Hodgkins lymphoma. He never really found a groove and continued to walk batters at a high rate. He's a fourth or fifth starter if he's still with Boston come April. Lester's name has been mentioned in trade talks with Minnesota. In either place, he'll be part of the starting rotation.

Lester is obviously a question mark entering the 2007 season in light of the lymphoma he was diagnosed with last September. He reports that he's cancer-free after treatment and is looking forward to spring training. Unfortunately, Boston has five set starters. He lived dangerously in his 15 starts in 2006, getting into trouble often via the walk. He's a cool customer on the mound, however, and often worked his way out of jams. He's a power pitcher with a low-to-mid 90s fastball, which is his out pitch. Of course, monitor him this spring to see how the illness has affected him.

When the Red Sox were negotiating the Josh Beckett deal, they told the Marlins that Lester was going nowhere. The team likes the athletic lefty, who has good movement on his low-to-mid-90s fastball, which he uses as his out pitch. He has an above-average change up, an 11-to-5 curve (low 70s) and worked on developing a cutter in 2005. He'll likely begin the 2006 season at Triple-A Pawtucket, where he can work to reduce his walks and continue to be a power strikeout pitcher. Lester is a hard worker and prepares well for each game.

Lester is still learning pitching mechanics and developing consistency, but the lefty is improving. Looking into his numbers, we see some good signs. He’s shown the ability to keep the ball in the park, and last season had a better K/9 ratio for Single-A Sarasota in the Florida State League. He should be moving up to Double-A, where we expect continued development.