Closers are the least reliable of all fantasy players. They can fall off a cliff from one year to the next, or lose their job and become worthless players you need to pull off your roster immediately. Every team has one but even when they are racking up saves, they can ruin your ratios and are particularly dangerous in head-to-head leagues.
Some fantasy analysts will prescribe to a "no saves" style of roster construction, but in the end someone has to take the closers. I leave where you draft them to you, but they should really be drafted in this order.
1. Kenley Jansen, Los Angeles Dodgers
Jensen is the best closer in the game, and underscored that status last year by improving his already elite strikeout rate. He has picked up at least 35 saves in each of the last four years, put up at least a 13.5 K/9 rate in those four years and put up an ERA under 2.00 in the last two years. If you are going to pay for saves, pay for Jansen.
2. Craig Kimbrel, Boston Red Sox
Kimbrel led all of baseball with a ridiculous 16.43 K/9 rate and managed to slash his walk rate as well, making him a WHIP monster as well as a strikeout contributor.
In 2018 he is set to be the K king again, but interestingly new Red Sox manager Alex Cora has talked about using him more in high leverage situations, potentially taking away a few save opportunities. Either way, Kimbrel figures to be an elite closer option in 2018, and while the strikeout rate may drop and the walks may tick up a notch, he is still a good step ahead of the rest.
3. Corey Knebel, Milwaukee Brewers
Knebel took the Brewers closing job last May and was an instant success.
Only Kimbrel, Jansen, and Chad Green struck out a higher percentage of batters faced than Knebel last year. He was a little fortunate with things like left on base rate and walked a few too many guys, but the hard-throwing righty has a filthy enough curveball to buckle knees and keep his strikeout rate up.
4. Roberto Osuna, Toronto Blue Jays
Osuna's high ERA last year may scare some people off, but it was a remarkable outlier compared to the rest of his stats. Some bad luck and a terrible strand rate inflated the ERA, while things like a big jump in ground balls, a dip in HR/FB rate and a big step up in strikeout rate should have pushed it down. Look for his ERA to bounce back in 2018.
5. Ken Giles, Houston Astros
Giles was a star in the regular season for Houston, but fell apart in the playoffs. It didn't cost his team, but he was barely used after blowing up early on. The Astros have a very deep bullpen, so Giles' leash may be short in 2018, but that playoff sample size is a very small one, and he was so good in the regular season that it would be hard not to see Giles cement his role early and march on to a good campaign in 2018.
6. Aroldis Chapman, New York Yankees
A big name, but not such a big star these days.
Chapman was electric at the start and end of the season for the Yankees, but in the few months in between he was fairly ordinary. Shoulder and hamstring issues hampered him for a lot of the year and robbed him of his effectiveness. He still has his fiery 100mph fastball but when it isn't moving, it can be hit. His postseason was strong and encouraging though. He could end up outperforming his draft price, but there should be some caution with him in 2018.
7. Cody Allen, Cleveland Indians
Allen is not an elite closer, but he has been reliably good for the Indians over the last four years. He lacks high-end control and can be homer-prone, but he has a strong strikeout rate and cut his walks down last year.
He is yet to break through the 35-save barrier, but the Indians will give him a lot of opportunities in 2018, making him a good option for your closer role.
8. Raisel Iglesias, Cincinnati Reds
2017 was Iglesias' first in the closer role for the Reds, and he did well with the opportunity. He induced a strong 13.9% swinging strikes with his plus fastball & slider and can mix a changeup in there as well. Iglesias converted 28 of 30 save chances and was often given the opportunity to work more than just one inning, which helps him rack up a few more strikeouts. He isn't likely to lead the Majors in saves, but he is a solid investment this season.
9. Wade Davis, Colorado Rockies
Davis got paid over the winter, inking a new three-year, $52m contract with the Rockies after a strong 2017 with the Cubs.
However, that 2.30 ERA was Davis' worst in four seasons, and at 32 that arm will decline. Davis saw a big rise in both walks and HR/FB rate last year, which is only likely to get worse now 82 of his games are at Coors Field. As a setup man for the Royals Davis was electric, as a closer less so, and there was another step back as a closer for the Cubs. I'm a little nervous about him this season, but there will be plenty of save chances for the Rockies, and he will get the first crack at them.
10. Felipe Rivero, Pittsburgh Pirates
2017 saw Rivero take up the closer's role for the first time and perform even better than people expected, at least to begin with. He struggled down the stretch, allowing too many line drives and hard contact, but his strikeout ability and solid history in the setup role should mean a bounce back year in 2018. The Pirates will not generate an elite number of save opportunities, but Rivero can help with your rates as well as provide saves and should have a long leash if he struggles.