Streaming is a time-tested approach prized by fantasy owners of all stripes. Categories in head-to-head leagues can often come down to the thinnest of margins, making the weekend a crucial time to think about streaming pitchers. Below are this weekend's best options -- all owned in 30 percent or less in either Yahoo!, CBSSports or ESPN leagues as of Thursday night.
• Jake Arrieta, Cubs -- Arrieta is one of the best stream options this weekend for owners chasing strikeouts. The righty has 28 strikeouts in 30 innings on the strength of a fastball that sits in the 93-94 mph range, a cutter that Fangraphs would rank as the eighth best in the league if he had thrown enough innings to qualify, and a changeup that boasts an 18.8-percent swinging-strike rate. He takes the ball for the Cubs on Sunday against the Marlins -- a team susceptible to the strikeout this year. They have a 22.5-percent strikeout rate, which is the sixth highest in the majors. Regulars Christian Yelich, Giancarlo Stanton, Garrett Jones and Marcell Ozuna all have individual strikeout rates north of 20 percent. The Marlins may touch Arrieta up a bit, but he's a good bet to post strong whiff totals on Sunday.
• Randy Wolf, Marlins -- The Marlins signed Wolf in the wake of Jose Fernandez' season-ending elbow injury, getting him a few tuneups as a reliever before sending him out as a starter. He got roughed up by the Brewers in his first start, but held the Rays to one run on three hits with seven strikeouts in six innings his last time on the bump. It's true the Rays are among the most punchless teams in the league, but the good news for Wolf is he'll face another one of those teams when he gets the ball on Saturday. The Marlins are on the North Side of Chicago this weekend, visiting a Cubs team hitting just .231/.299/.361 with a .294 wOBA and 79 wRC+. They also have the league's second-highest strikeout rate at 23.2 percent. Wolf's not a guy you want to keep around beyond this weekend, and he matches up with Jeff Samardzija, but he can really help you no matter what your late-week pitching needs.
• Henderson Alvarez, Marlins -- The idea with Alvarez is similar to that with Wolf: pick on the Cubs. However, Alvarez deserves a longer look in deeper leagues. He doesn't strike out very many batters (just 45 in 75 2/3 innings), but he doesn't walk anyone or give up home runs. He's issued 16 non-intentional walks and surrendered four long balls this year. He starts Sunday, and is a great stream option against a Cubs offense that has really struggled this year. If you're in a league with 14 or 16 teams, you might want to consider keeping him on your roster beyond this weekend as well.
• Blake Treinen, Nationals -- Treinen finds himself in the Washington rotation by virtue of Gio Gonzalez' injury, and he has acquitted himself well in two starts. He has allowed two runs on 11 hits in 10 2/3 innings against the Dodgers and Pirates, and even pitched around five walks in Pittsburgh. Treinen's scant fantasy value is soon to evaporate with Gonzalez headed out on a rehab assignment, but he can be plenty useful for fantasy owners when he takes the mound against the Padres in San Diego on Saturday. We all know the benefits of pitching at Petco Park, and the Padres have been, by most measures, the worst offense in the majors this year. They're hitting .221/.283/.351 as a team. The batting average and OBP rank last, and the slugging percentage ranks 29th, which is two points ahead of the Mets. Their .282 wOBA is the worst in the majors and their 79 wRC+ is tied for last with the Cubs. Seth Smith has been incredible this year, but when he's by far the best bat in your lineup, you're in serious trouble. He's typically not a fantasy option, but Treinen, like most any pitcher in the league, can take advantage of the Padres.
• Danny Duffy, Royals -- There's an argument to be made that Duffy is more than just a stream option in deeper leagues. Take away starts against the Angels and Astros in which he gave up 10 runs in 10 innings, and he has allowed just two runs in 23 innings as a starter. Of course, we can't just pretend those starts didn't happen, but he has been a strong positive for his owners four of his six times out. If you're in a deep league in need of some help in your rotation, think about kicking the tires on Duffy his next few turns. Regardless of your league size, however, he makes a solid stream play this weekend. The Yankees, whom he will oppose on Saturday, have been just average on offense this year, posting a wOBA (.311) and a weighted runs created plus (93) that rank in the bottom half of the league.