There's a golden rule when it comes to season-long fantasy baseball that is almost universally accepted: Don't pay for saves.
This shows up in drafts every season. No reliever has an average draft position (ADP) higher than the 55th overall pick, according to early ESPN ADP data. And that's for the elite guys who have track records of mowing down dudes with no regard for the feelings of others.
As for a guy entering his age-23 season with just 51 2/3 innings of big-league ball under his belt? Not a chance you're reaching for him before the late rounds.
Edwin Diaz appears to be an exception to this line of thought. He's not an established closer with a long history of elite production, but he's eighth in reliever ADP on ESPN, two spots ahead of Craig Kimbrel, who has had at least 30 saves in six consecutive seasons.
Diaz's draft capital outweighs his profile. But he's still worth reaching for.
As strange as it may seem, it's entirely possible that Diaz is going too low rather than too high. His sample in the majors may not be robust, but dude lit souls aflame when he was on the bump, and he's in line to close for a potential playoff team. There's abundant value in that.
Let's take a deeper look at Diaz to see why this guy should be on our radars heading into drafts, even if his profile may be a little scary.
Strikeout Savant
In 2016, the average major-league reliever had a strikeout rate of 22.7%. Aroldis Chapman -- who had an average fastball velocity of 100.4 miles per hour -- was at 40.5%.
Diaz's strikeout rate was 40.6%, the fourth-best mark in baseball among those with at least 50 innings pitched. That'll make your eyes pop.
Even though Diaz's sample was small, that doesn't mean we shouldn't trust it. Strikeout rates for pitchers stabilize after 70 batters faced, according to FanGraphs, and Diaz faced three times that many at 217. This is a legitimate number.
He also backed it up by inducing swings and misses on 18.5% of his pitches, the fourth-best mark in the league. This is where you would look to see if a strikeout rate is fluky, but Diaz passes with flying colors.
If you want to justify taking a closer relatively early in drafts, he had better be able to bathe in strikeouts while dropping anchor on your ERA and WHIP categories. Diaz has the strikeouts, and that'll translate into production elsewhere.
For comparison, let's break the top eight relievers in ADP down by their advanced metrics from last year. Skill-interactive ERA (SIERA) is an ERA estimator that will give us better forward-looking information on relievers due to their small samples. Because saves are also important, each team's projected win total is also included, courtesy of numberFire's preseason projections. All ADP data again comes from ESPN.
| Reliever | Overall ADP | SIERA | Strikeout Rate | Walk Rate | Proj. Team Wins |
|---|---|---|---|---|---|
| Kenley Jansen | 55.1 | 1.60 | 41.4% | 4.4% | 88 |
| Aroldis Chapman | 58.5 | 1.95 | 40.5% | 8.1% | 78 |
| Zach Britton | 67.8 | 1.74 | 29.1% | 7.1% | 81 |
| Mark Melancon | 80.3 | 2.83 | 24.1% | 4.4% | 87 |
| Seung Hwan Oh | 82.2 | 2.42 | 32.9% | 5.8% | 86 |
| Wade Davis | 95.2 | 3.34 | 26.7% | 9.1% | 92 |
| Roberto Osuna | 95.4 | 2.87 | 28.5% | 4.9% | 85 |
| Edwin Diaz | 103.2 | 1.82 | 40.6% | 6.9% | 85 |
If we're looking at this from a tiering perspective, it's pretty clear that Diaz's ADP is an anomaly relative to his peers. He had the third-best SIERA and second-best strikeout rate of this group, yet he's the eighth off the board.
Let's go back to the original discussion about Diaz's similarities to Chapman. As you can see in the chart above, they offer a lot of the same at a wildly different price.
| Reliever | Overall ADP | SIERA | Strikeout Rate | Walk Rate | Proj. Team Wins |
|---|---|---|---|---|---|
| Aroldis Chapman | 58.5 | 1.95 | 40.5% | 8.1% | 78 |
| Edwin Diaz | 103.2 | 1.82 | 40.6% | 6.9% | 85 |
Diaz has better marks in every single category than Chapman, and his team is projected to win an additional seven games. This is before we even mention that the Seattle Mariners' park is one of the best for pitchers in the league, further aiding Diaz's ERA potential. Chapman's track record makes selecting him first fully understandable, but the gap between the two should not be nearly this large.
For many people, the costs on those top-level relievers will be too high for investment. However, you can get a player who had similar abilities last year playing on a solid team for a much cheaper price. Even the most stringent "don't pay for saves" believers have to be intrigued by that.
Conclusions
It's true that relievers don't carry the same value for fantasy as starters do, thus pushing down their costs and lowering the incentive to pay a premium on any player. But the market says high-level relievers who contribute in multiple categories should be going much higher than where Diaz currently is.
We don't have a huge sample on Diaz in the big leagues, but what he did last year compared favorably to the game's best. Additionally, his peripheral stats indicate that we shouldn't expect a major regression there in his second season. Add in his solid situation with a good team and a great park, and this guy looks like a bargain.
Track record is important for fantasy, and we should never simply disregard it. But the market appears to be overreacting to Diaz's lack of experience. At his current price, all potential risks are already baked in, but his upside of being one of the best relievers in baseball is not. That's enough to justify taking him a bit ahead of where he's going.