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What the Astros SHOULD Really Do For a Left Handed Relief Pitcher

Every year at this time of year there seems to be the same need for the Houston Astros franchise- a GOOD Left Handed Relief Pitcher. While the Astros' bullpen overall has been very good so far, this year is no exception. We may need to take you down a journey of understanding expected stats vs. actual performance. Over the past few years it has become clear to me that the Astros base many decisions and plans upon EXPECTED performance statistics. Why? Pitching statistics, especially partial season pitching statistics for relief pitchers are potentially NOT predictive to what a player will do the rest of the season. Baseball plays are a combination of execution, luck, and probably a host of environmental and stadium factors, One would be better served using a PREDICTIVE statistic like xwOBA or xERA which predicts what a NORMAL performance level would be for a pitcher based on the quality of contact he able to avoid. If this sort of thinking is not for you or you simply don't believe in expected statistics, I simply ask that you stop reading this article. The rest of this will not be for you.

This article will closely model the articles on catcher and first base.

This article will do three things

  • Make the case that a change at LHRP IS needed

  • Explore the reasonable and best options to upgrade at LHRP

  • Define real and fair trade deals for BOTH sides

Why the Astros need to improve at Left Handed Relief Pitcher

If you are continuing, lets start with this table from the Mid-Season Report.

Notice all of the blue in the wOBA gap vs. LHH column especially among the bullpen. Notice how the xwOBA vs. LHH column is not near as red. This means the bullpen WOULD NOT be expected to be as good for the rest of the season as they have been so far.

What would the difference potentially be? Let's look at xERA. EVERY pitcher in the bullpen is expected to have an ERA vs. LHH worse than their current ERA. Four of them have expected ERAs more than 1.2 runs higher. THAT is significant. Most of the bullpen is expected to be worse against RHH too.

What do the projection systems suggest the second half ERA will be?

The second half bullpen is projected to be OK but not near as great as the first half.

Putting it all together, I believe the Astros need a very effective LHRP that can get LHH out. Who?

What Are the Reasonable and Best Options to Upgrade at First Base

Let me give you my criteria first. LHRP targets must:

  • Pitch for a team not likely to make the postseason

  • Have pitched at least 100 pitches to both LHH and RHH (I wanted at least some sample size)

  • Have a GOOD wOBA and xwOBA vs. LHH (Set at <0.260)

  • NOT be terrible in wOBA and xwOBA vs. RHH (set a <0.320)

  • Relief Pitchers only

I pulled these statistics for ALL MLB LHP. There are 194 pitchers on this list. I applied these filters and there are SEVEN that meet this criteria. Of these seven, four pitch for contending teams.

Here are my three LHRP targets

I would go with either of the first two options.

What are Real and Fair Trade Deals for BOTH Sides

So what would a fair deal be for Chafin or Mantiply? This week we listed the for the Astros. PLEASE take a moment to read that article here before proceeding.

  • Andrew Chafin- 32 years old

    • Analysis- Chafin has been a consistent target of mine for over a year. His 2.30 ERA is confirmed by his 2.26 xERA. As illustrated in the filters his wOBA and xwOBA are great against BOTH LHH AND RHH. He is signed for $6.5M AAV for 2022 and 20223. has Chafin listed at 4.3. Let's target 50% premium (6.5)

    • What the Tigers want- The Tigers are a team with a future but due to injuries that future is at least a year away. I believe they would like young talent that can help the team build.

    • Trade proposal- Chafin for Perez (3.0), Solomon (2.9), and a lower level prospect

    • Likelihood of Trade- 6

  • Joe Mantiply- 31 years old

    • Analysis- Mantiply is having his best year and there is some risk to if the performance is sustainable. His 2.31 ERA is confirmed by his 2.26 xERA. As illustrated in the filters his wOBA and xwOBA are great against BOTH LHH AND RHH. He has been even better than Chafin vs. RHH. He is not even eligible for Arbitration until 2024 and won't be a free agent until after the 2026 season. Mantiply is the riskier but potentially longer reward as a good LHRP. It is not clear that the Diamonbacks would be willing to trade him. has Mantiply listed at 3.8. Given the years of control you might have to double that- 7.6.

    • What the Diamondbacks want- The D'backs need talent and a lot of help pitching.

    • Trade proposal- I think the deal would be similar to the Chafin deal. Mantiply for Perez (3.0), Solomon (2.9), and Muchinski (1.2), and a lower level prospect

    • Likelihood of Trade- 4

So there you have it. My TWO best options for the Astros to upgrade at LHRP. I was shocked I did not come up with better or more options for a LHRP. I would do a deal quickly, but I suspect the Astros won't.

What trade target would you go after and what deal would you propose?

As stated earlier, time may push more teams into sell mode but with very few viable trade target options, the team needs to monitor additional opportunities closely. We will revisit and revise this article as the trade deadline approaches.

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