[luckymann]

The third and, arguably, most useful application for this is what we'll call a "target search", whereby I give the AI agent certain criteria and ask for its best selections that match them.

So, in this example, I gave the AI the full league player list and asked it for the best 10 groundballer LH relievers.

Here's what it came up with:


Here is a target search based on the attached leaguewide pitching file, with the pool filtered to left-handed relievers and then weighted toward true groundball utility rather than just raw GB%.

I did not simply take the 10 highest ground-ball rates. I prioritised pitchers whose groundball profile actually looks usable in a front-office context. That means GB% and GB/FB were the starting point, but I also weighed K%-BB%, HR/9, FIP-/xERA, contact quality allowed, workload and leverage. In practical terms, I was looking for left-handed relievers who keep the ball on the ground and still look like real pitchers, not one-dimensional sinker specialists who are surviving on noise.

For meaningful evaluation, I also leaned away from tiny-sample names and toward pitchers with enough innings to say something useful.

Top 10 Groundball Left-Handed Reliever Targets

1. Tim Hill, STL
Hill is the cleanest fit for the brief because he combines elite groundball shape with genuinely strong run-prevention indicators. In 31.0 IP he owns a 56.5% ground-ball rate and a 2.18 GB/FB ratio, both near the top of this subset, but the key is that the rest of the line supports it. He has a 213 ERA+, 80 FIP-, 2.22 xERA, 0.3 HR/9 and just a 4.5% HR/FB. That is exactly what you want from a groundball lefty: not just grounders, but a real ability to suppress damage. The contact quality is excellent at 81.2 EV, 1.2% barrel rate and 11.8% hard-hit rate, which is one of the best weak-contact profiles in the file. He is not overpowering, with a 19.2% K rate and 6.2% K-BB%, but for this role he does not need to be. The 1.65 pLi also tells us he is already being trusted in leverage. This is the best blend of fit, performance and specialist utility in the pool.

2. Brian Fuentes, CHC
Fuentes is the best version of a groundball reliever who still misses bats. He is not quite as extreme on grounders as Hill, but 47.9% GB and a 1.47 GB/FB ratio still make him a legitimate fit, and the bat-missing component is much stronger. In 49.1 IP he has a 27.9% K rate, 15.9% K-BB%, 40.0% whiff rate, 181 ERA+, 79 FIP- and 2.67 xERA. That is a real late-inning profile. He is also keeping the ball in the yard at 0.7 HR/9 with only a 10.5% HR/FB. The contact quality is good rather than elite, with 83.7 EV, 6.8% barrel rate and 23.9% hard-hit rate, but that is more than good enough paired with the strikeout ability. If the goal is not just groundballs but a left-handed reliever who can handle leverage, Fuentes is one of the best targets in the file.

3. Leo Kiely, PIT
Kiely makes the list because he is a true workhorse groundball lefty with a stable, useful shape. In 101.0 IP he has a 51.8% ground-ball rate, 1.84 GB/FB ratio, 101 ERA+, 86 FIP-, 4.35 xERA and 0.6 HR/9. He is not flashy, but he is durable and the profile is coherent. He walks only 5.5% of hitters, which matters because his strikeout rate is modest at 12.8%. The low strikeout rate keeps him from ranking higher, and the contact allowed is merely acceptable rather than dominant at 84.1 EV, 9.5% barrel rate and 28.1% hard-hit rate. But if the mandate is to find a left-handed groundball reliever who can cover real innings and avoid self-destruction, he is a valid target. He looks more like a steady support arm than a weapon, but those arms have value.

4. Darrell Jackson, SRC
Jackson is a very solid groundball target because the profile is cleaner than the surface name value might suggest. He has 44.0 IP, a 51.1% ground-ball rate and a 1.58 GB/FB ratio, while also carrying a 103 ERA+, 85 FIP- and 3.65 xERA. The shape is good: 0.4 HR/9, 4.4% HR/FB, 83.4 EV and a low 16.5% line-drive rate. He is not a strikeout reliever, with a 15.8% K rate and 5.3% K-BB%, but he is functional enough around the zone to make the contact-management approach work. The barrel rate at 8.6% is a little high relative to the rest of the line, so there is some fragility here, but the total package still reads as a useful left-handed groundball arm. He is not a primary target in the same tier as Hill or Fuentes, but he belongs in the top 10.

5. Randy Jones, BAL
Jones is one of the more role-specific groundballers in the file. The argument for him is obvious: 71.2 IP, 51.5% GB, 1.60 GB/FB, 107 ERA+, 3.25 xERA and only 83.7 EV allowed. He is also not beating himself, with a 5.5% walk rate. The argument against him is equally obvious: he has very little bat-missing ability, with only a 9.4% K rate and 3.9% K-BB%. That means he has to live entirely on shape and contact management. To his credit, he mostly does. The 1.0 HR/9 is acceptable, the 9.5% HR/FB is fine, and the launch angle allowed is just 9.8 degrees. This is a pure contact-management groundball lefty. He is not for every roster, but if you want a sinkerball-style relief arm who keeps games under control and lets the defence work, he is a legitimate target.

6. Les Rohr, ARI
Rohr is a very interesting acquisition candidate because the contact-quality profile is strong and the home-run suppression is excellent. In 27.0 IP he has a 48.2% ground-ball rate, 1.74 GB/FB ratio, 165 ERA+, 81 FIP-, 3.23 xERA and only 0.3 HR/9. The quality of contact allowed is among the best in the pool: 81.4 EV, 4.8% barrel rate and 22.9% hard-hit rate. He is not an especially dynamic bat-misser, with a 16.5% K rate and 6.1% K-BB%, but he has enough of a floor to make the groundball profile useful. The only reason he is not ranked even higher is that the sample is smaller and the line-drive rate at 24.1% is a bit higher than ideal. Still, this is a strong target if you want a lower-cost lefty whose profile may be better than his name value.

7. Dean Stone, SD
Stone makes the list because he offers one of the cleaner weak-contact groundball profiles in the group, even if the sample is still modest. In 23.1 IP he has a 46.4% ground-ball rate, 1.78 GB/FB, 143 ERA+, 85 FIP- and 2.48 xERA. His contact suppression is excellent: 83.4 EV, 1.4% barrel rate, 13.0% hard-hit rate and just 0.4 HR/9. He does not overpower hitters, with a 16.5% K rate and 4.1% K-BB%, so this is not a dominance play. It is a shape-and-contact play. The 1.48 pLi is notable, because it suggests he is already handling meaningful spots. The sample size is the obvious caution, but in terms of pure groundball lefty functionality, he deserves the placement.

8. Bob McClure, LAD
McClure is one of the most groundball-heavy arms in the file, and that gets him onto the list despite some real concerns. In 33.0 IP he has a 57.3% ground-ball rate and a 2.46 GB/FB ratio, both elite. He also has a decent 20.2% K rate and 32.9% whiff rate, so on paper there is more than just sinkerball volume here. The problem is the quality of contact when he does get hit: 86.0 EV, 34.0% hard-hit rate and a 12.5% HR/FB. His actual performance line is weak as well, at 79 ERA+ and 4.18 xERA. So why include him? Because true groundball lefties with this level of batted-ball tilt and enough strikeout ability are not common, and if the contact quality can be stabilised at all, there is something to work with. He is more of a projection or refinement target than a polished acquisition.

9. Braxton Garrett, BAL
Garrett is a very good example of why this search cannot be run on GB% alone. On one hand, he is exactly the sort of left-handed groundball reliever clubs look at first: 49.7% GB, 2.29 GB/FB, 39.1 IP, 84.7 EV and only 4.9% barrel rate. On the other hand, the run-prevention line is mixed: 80 ERA+, 103 FIP-, 4.60 SIERA, 3.88 xERA and 1.4 HR/9. The reason he still makes the top 10 is that the shape is strong enough to believe there is still usable value here. The strikeout and walk line is fine, with a 15.8% K rate, 8.4% walk rate and 7.4% K-BB%, and the fly-ball rate is very low at 21.7%. The issue is that when the ball does get elevated, the damage is real, with a 19.4% HR/FB. This is a target if you believe the homer rate is the outlier rather than the skill.

10. Red Bird, SEA
Red Bird rounds out the list because he is a stable, low-walk left-handed reliever whose contact profile fits the groundball brief well enough, even if he is not as extreme as some of the names above him. In 24.2 IP he has a 47.6% ground-ball rate, 1.56 GB/FB, 1.99 xERA and an excellent 14.2% K-BB%. He walks only 3.8% of hitters, which immediately gives him a strong floor, and the contact allowed is good at 82.2 EV, 4.9% barrel rate and 24.4% hard-hit rate. The actual results are less impressive, with an 84 ERA+ and 1.1 HR/9, which is why he ranks lower. But from a skill perspective, there is enough here to be interested. This is the sort of arm whose value may be hidden by a line that has not fully caught up to the underlying control and contact suppression.

Just Missed

Fred Link missed the top 10 despite a 52.4% ground-ball rate because the damage indicators are shakier than I’d want from a true target: 1.8 HR/9, 10.0% barrel rate and only a 6.7% K-BB%. That is a groundballer, but not one I trust.

Antonio Bastardo missed because, while he is probably one of the better left-handed relievers overall, he is not really a groundball specialist in this context. His 40.7% ground-ball rate is too light for the specific brief, even though the strikeout profile is excellent.

Shawn Estes and Doug Davis both had credible cases, but they sat a tier below the final 10 either because the strikeout-walk profile was too ordinary or because the overall contact-management line was less convincing.

Front-Office Summary

If the priority is a true groundball left-handed reliever, Tim Hill is the best fit in the file. He has the strongest combination of ground-ball shape, contact suppression, home-run control and leverage utility. Brian Fuentes is the best higher-octane option because he gives you real strikeout power without sacrificing the groundball fit. Leo Kiely, Darrell Jackson and Randy Jones are the steadier support-tier targets, with Jones in particular as a pure contact-management specialist. Les Rohr and Dean Stone are appealing lower-profile options whose contact quality lines are better than their market perception might be. McClure and Garrett are more developmental or bet-on-shape targets, while Red Bird is a floor play built on control and weak contact. If I were narrowing this to the strongest acquisition targets overall for the brief, the first calls would be Hill, Fuentes, Rohr and Jackson.


I see this as being super handy to whittle down potential FA adds or when looking for undervalued guys around the traps.

If you have your league set up with feeders etc and the setting applied to track advanced stats at all levels, then I suppose you could also use this for assessing potential draftees. But the league would have to be quite mature for this to work effectively, I'd think.