Winning a fantasy baseball championship requires hard work. It's a six-months-long grind, which doesn't even consider the bountiful hours of draft preparation. There is no letting up in September, where outhustling your leaguemates can be the difference between winning and having to "try again next year."
Streaming the right pitchers is essential. Often, the choice comes down to a better pitcher facing a better lineup, or a lesser pitcher matched up against a lesser lineup. There really isn't any reason to lean in one direction over the other. As such, having a feel for the associated lineups at that time helps drive the decision.
Playing matchups for hitters, especially in daily leagues, is the key to success. Using batters with the platoon edge on the starting pitcher is one of the most common means of optimizing a lineup. With bullpens covering more innings in today's landscape, choosing hitters facing a team with a suspect bullpen is a wise way of strengthening a fantasy lineup.
Meanwhile, in category-based leagues, selecting individuals with a better chance of stealing a base against that team's battery helps fortify the SB category early on in the matchup so that you can use that particular roster spot on a more complete player the rest of the week.
What follows is a series of observations, specific to different aspects of roster management. The focus will be on changes to a team's production relative to their season-long numbers. Trades, injuries and minor-league callups all contribute to current roster compositions. Researching how a team has fared against right-handed pitching this season may not be an accurate reflection of their present potential.
Lineups to target when streaming pitchers
There are two primary stat considerations when selecting a pitcher for a spot start: opponent wOBA and K%.
Strikeouts are incorporated in almost all fantasy scoring systems, so not only do they help frame a hurler's potential for success, but they also count directly in the standings. K-BB% is a truer measure of a pitcher's potential and is a better means of gauging a pitcher's ability to limit base runners and scoring. However, walks are part of the wOBA formula, so concentrating on just K% is preferred.
Speaking of wOBA (weighted on-base average), it's a souped-up version of OBP, where each component has a coefficient relative to how it contributes to the current run-scoring environment. It is crucial to note that wOBA is not park corrected. That is, two players may have the same wOBA, but one may actually be a better hitter if their home park deflates offensive production. That said, we aren't comparing the relative merits of individual players or teams, we care about their actual production, so the park effects are relevant.
This brings up a common mistake made by many when streaming pitchers. Often, using a hurler in a "hitter's venue" is avoided. Sure, in extremes it's best to avoid Coors Field, but a team's lineup strength is the key, not their home venue. Using the opponent's home wOBA when streaming a pitcher on the road is the proper consideration, since the park factors are already baked into the team's wOBA.
Streaming LHP at home
The Chicago White Sox, Colorado Rockies and Detroit Tigers are by far the best lineups to target. Their road wOBA versus southpaw pitching since August 1 is, by far, lowest in the league. All three teams are also fanning at an elevated clip.
The San Francisco Giants and Cleveland Guardians make up the next tier. The Giants have recorded the highest K% in this scenario.
Streaming RHP at home
The Milwaukee Brewers and the Rockies are the optimal lineups to pick on when deploying a righty for a home start. However, even though they sport the lowest road wOBA facing right-handers since August 1, the Brewers have whiffed at a clip below the league average, so your spot starter isn't assured of padding his strikeout total.
The Washington Nationals, New York Yankees and Los Angeles Angels encompass the next group. Like the Brewers, the Nationals have generated minimal offense when facing a righty on the road but have a K% that sits below the league average.
Streaming LHP on the road
Something must be in the Buckeye State air with the Guardians and Cincinnati Reds exhibiting the worst home wOBA facing left-handed pitching. Curiously, neither lineup is striking out excessively, which is an important element of the decision.
If you want strikeouts and poor production, the Oakland Athletics and Chicago Cubs have both a low wOBA and high K% at home against left-handers since the trade deadline.
Streaming RHP on the road
The Giants are in a tier by themselves with, by far, the lowest home wOBA versus right-handed hurlers. Not only is their offense struggling, but they also play in an extreme pitching venue. The White Sox and Guardians are also solid lineups to target for a righty away from home as they both fan at an above-average (but not bloated) clip.
Lineups to avoid when streaming pitchers
Streaming LHP at home
The Atlanta Braves, Houston Astros, Seattle Mariners and Toronto Blue Jays have been crushing lefties on the road. Curiously, the Mariners are striking out at a high rate, but they're also walking, and hitting homers at an above-average pace.
Most try to avoid the Yankees in the Bronx, but lately they've been pounding southpaws away from home.
The Minnesota Twins, Los Angeles Dodgers and Baltimore Orioles all have lineups that are best avoided when considering a lefty at home.
Streaming RHP at home
Steer away from using a righty when the Astros are visiting. They're barely striking out and are walking a ton in these scenarios.
The Tampa Bay Rays, Boston Red Sox, Mariners and Braves are also risky teams against which to deploy a right-handed spot-starter at home.
Streaming LHP on the road
The Braves, Astros, Mariners and Blue Jays have been extremely productive for home games with a southpaw on the hill. The Yankees are also a dangerous lineup to pick on for home games against lefties, with the Twins, Dodgers and Orioles joining them in that next tier.
Streaming RHP on the road
The Astros and Rays make the "avoid list" for home tilts against righties, and they are also potent facing right-handers in their home venue.
The Mariners, Red Sox and Braves comprise the next tier. Again, Seattle is scoring a lot, despite a high strikeout rate.
Stolen bases
Research conducted earlier in the season demonstrated that a team's propensity to run is more relevant than the ability of the opposition to catch would-be base-stealers. However, the main lesson here is to not be afraid to use an established base-stealer against a battery which has not been yielding as many steals. Yes, the quality of the battery is still something of paramount importance to consider when determining whether or not to start a particular player capable of swiping a bag, but when it comes to the league's leaders, it should not be a deterrent.
Teams running the most
The Kansas City Royals lead the league in steals since August 1, with 43. Bobby Witt Jr. has 10, but he's in your lineup regardless. Dairon Blanco also has 10, so this is the ideal player to sneak into a Monday or Thursday lineup when there are probably holes from off days.
The Reds, Mariners and Guardians have also been active on the basepaths lately. TJ Friedl, Jose Caballero and Andres Gimenez are the best targets from this trio of teams.
Teams running the least
The Giants have merely one pilfer (courtesy of Thairo Estrada) since August 1.
The Marlins are the only other team with single-digit steals since the trade deadline, which is odd considering that Jazz Chisholm Jr., Jon Berti and Joey Wendle have all demonstrated the ability to steal a base.
Batteries to target
The Mets have only thrown out two runners in 34 tries and the Guardians just three in 34 attempts since the trade deadline. Don't hesitate to target these two clubs for steals, even with Noah Syndergaard no longer with Cleveland. The Guardians bullpen is collectively poor at limiting stolen bases.
The White Sox have yielded the most steals since August 1, but their 77.6% success rate against is actually one of the better marks in the league. Teams have simply attempted, by far, the most steals against the White Sox.
Braves catchers have a poor success rate throwing runners out, but teams rarely attempt to steal against them since they're usually playing from behind.
The Padres, Pirates and Blue Jays, Yankees and Astros also have recorded high success rates of catching would-be swipers of late.
Batteries to avoid
This just in: Adley Rutschman is good at baseball. Not only is he one of the best hitting backstops, but he's a plus framer and is the best at throwing out those brave enough to attempt to steal when he's behind the dish.
The Athletics, Rangers and Rockies are also batteries to avoid with fringe base-stealers.
Reliever Considerations
With 41.5% of all innings covered by relievers, it's necessary to account for bullpens when streaming hitters, and maybe when appraising the chance that a starting pitcher might earn himself a win. The problem is that bullpens are composed of long men, a setup group and a closer. Perhaps an even better categorization for our purposes is: those used in close games versus those appearing when the team is either winning or losing by a wide margin. Relying simply on bullpen ERA is misleading. With that in mind, here are some recent bullpen trends.
Bullpens on the rise
"The rich get richer" with the Dodgers bullpen having improved the most over the past several weeks.
The next tier consists of the Nationals, Astros, Braves and Brewers, with Washington being most interesting. Granted, you're not worrying about using batters with Patrick Corbin on the hill, but if you're on the fence facing Josiah Gray or MacKenzie Gore, keep in mind the Nationals relievers have been better since August 1.
Bullpens on the decline
The Angels, Rockies and Red Sox bullpens have performed the worst, relative to how they were doing before the trade deadline.
The next tier are the hapless Mets, followed by the White Sox. Don't expect a ton of saves from these guys.
A word of warning
"A little over a month" may seem like a significant sample of games. However, when it's parsed into smaller splits like "home and away" and "versus right- and left-handed pitching," there is a lot of variance. It's best to use the above information as a starting point for your research. Particularly in September, lineups are in flux. Teams are auditioning players for the future, and injuries continue to mount.
Also, beware of seemingly contradictory information. There are a few instances of a team scoring runs while also striking out a lot or struggling to score despite fanning at a low clip. Sometimes, this is a sample-size blip and not a team characteristic. A productive team could be lucky, while a struggling offense could be stroking a bunch of "at 'em" balls. In these instances, expand the sample to better access the element of luck.
Again, winning is hard, and it requires both time and effort. Take the next step and research the most recent lineups and trends before making your final decisions informed ones.