We are halfway through June and the time to be making moves to improve your fantasy team is now. Today we are going to dig into the trade values of a couple of pitchers off to terrific starts that carry red flags: Patrick Corbin and Sean Doolittle. I will also answer a few "Rapid Fire" trade questions and dive into the value of Jose Altuve, Andrew Benintendi, and Justin Upton. Be sure to send you trade questions and trade offers to me @MattWi77iams on Twitter for a chance to be included in next's weeks "Making Moves" article.

Trading is the most creative and fun way to improve your fantasy baseball roster, but also the hardest. You have to be able to value your own players objectively while accurately gauging how your fellow league owners value their own players. It is a battle of strategy, risk, and chance that can pay off in a big way if you know how to approach each situation. Be sure to have reasonable expectations and make offers that benefit both teams.

"But wait, I want to win the trade and fleece the other guy." I hear this all the time and it is a bad attitude to have if you want other players to deal with you again in the future. People value their own players higher than anyone else does, it's just the way it is. You don't want to insult another owner and gain a poor reputation, otherwise they will see you your trade offer in their email and simply delete it. Ever send an offer and not get a response? That is why. It is important to make trade offers that make sense for both sides while making your team better.

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The Mailbag Scoring System

Every week, I will be breaking down trade values as well as trade offers sent in by RotoBaller readers to shed some light on how to make the best deal for your team. I will be grading trades that have been sent in using the classic letter system. Here are examples of what those grades might mean:

A: The reader won the trade. No risk, no downside. All victory.

B: The reader won the trade, but it was fair enough.

C: The trade was even for both sides and could go either way.

D: Even though the move may have filled a need, it was a poor return

F: What was the reader thinking?

V: Good or bad, this trade is likely to be vetoed. (I do not condone vetoing trades.)

If you want me to grade your trade, send your fantasy baseball trade questions on Twitter to @MattWi77iams. Now, let's take a look at some trades you may be looking at this week in fantasy baseball.

Who's on the Block This Week?

Patrick Corbin (SP, Arizona Diamondbacks)

Patrick Corbin came out of the gate this season as one of the top starting pitchers in baseball. Through April the Diamondbacks righty held a 1.95 FIP to go with a 36.7% strikeout percentage (11.75 K/9) and 4.7% walk rate. Although the level of success may not have been predicted, the performance did not come as a big surprise to the many who had Corbin pegged as a major breakout candidate in 2018.

To no one's surprise, a bit of regression occurred in the months following leaving the Arizona right-hander with a 3.10 ERA, 2.72 xFIP, and a 31.8% strikeout percentage (11.38 K/9) to go with a 7.2% walk percentage. The slight step backward could be easily explained by a simple normalization of Corbin's BABIP against. Through the end of April, his BABIP was sitting on .222, which increased in May to .274, and then again this month to .303. Seems like an easy enough explanation, right? Well maybe not as easy as fantasy owners would like it to be.

The regressions also came with a concerning trend with Corbin's strikeout and walk rates, going in the wrong direction slowly each month. The 36.7% strikeout rate he enjoyed in April dropped to 29.5% in May, only to fall further in June to 24%. Corbin's walk rate on the other hand, has doubled from the 4.7% in April to 10% in June. This new change in metrics also came with a considerable jump in the hard contact allowed by Corbin. All in all, this could not be simply explained away by BABIP. Something else was happening.

Velocity. This is the issue. This does not come as a shock to many as this tidbit has been "out of the bag" for some time now. However, in case you are new to the party I will give you the specifics. The Diamondbacks righty saw a drop of over three miles per hour in max velocity from April to May, dropping from 95.69 mph to 92.47 mph (dropping a bit further in June, shown in the chart below). This is a concern as a sudden drop in velocity typically comes with other issues, usually health related. Luckily, nothing has proven to be physically wrong with Corbin so far.

All in all, even with the red flags and regression Patrick Corbin has still been a very effective pitcher. If you simply take his worst month of the season he was still holding a 3.69 FIP and 3.36 xFIP. Hardly a "bad" pitcher wouldn't you say. Still, the constant drop in velocity coupled with a bad trend in performance analytics should have been reason enough to trade Corbin to someone who still thinks he is the elite pitcher who showed up to start the season.

“Matt, I recently traded Patrick Corbin for Justin Upton. I was in need of OF help and I'm anticipating some regression for Corbin, thoughts on the deal?”

Well, the regression has already occurred my friend. The way this question was phrased may go to show how Corbin's true regression may still be hidden to some given how well he is still pitching on the surface. Either way, this is a good deal for the reader. If you needed an outfielder you can depend on to perform as expected, Justin Upton is your guy. He may be streaky for H2H formats, but in roto you can carve his statistics in stone. Upton is off to a fantastic start, batting .254 with 15 home runs so far this season. This would put him on pace for a career high in the power department which was set last year. The bottom line here is that Patrick Corbin is still a good pitcher, but one that comes with a few red flags. You do not need to rush to give him away or anything like that. You should try to test the market to see if you can cash-in on his tremendous start though.

I would grade this trade an: B

Sean Doolittle (RP, Washington Nationals)

Let me first start off by saying, "Don't Pay For Saves!" This is a well-known theory to fantasy baseball owners and one that holds true in all formats. "But Matt, my league favors closers and it's hard to get them." No, I am not buying it. Your league is the same as all leagues. Closers come and closers go. Injuries, trades, and changes in hierarchy happen constantly. It is almost guaranteed that a couple of the more effective closers in baseball at the end of this season may not even have the job right now as we speak.

That being said, Sean Doolittle has been amazing this season. The Nationals southpaw is having close to, if not, the best season of his career. Doolittle looks just as dominating as the up-and-comer we saw in Oakland back in 2014, sporting a 1.52 ERA, 1.74 FIP and a shiny 12.44 K/9. All of this while allowing just 0.91 BB/9. He is an elite closer.

We all know the "but" with Doolittle though. The man's body is made out of Troy Tulowitzki. The Washington left-hander has gone on the disabled list every season since 2014 with either a torn rotator cuff or shoulder strain in his pitching arm. It is sad to watch from a player as talented as he is. Either way, this makes Sean Doolittle a smart "sell-high" for anyone who owns him. Can you predict injury? Not really. You can certainly make a reasonable assumption based on documented history though. Sean Doolittle may very well have an injury free season, closing for one of the top teams in the National League. However, if someone will pay for his current production it would be wise to take advantage. (BAA, batting avg. against since 2015 seen below)

"I need a closer and someone asked for my Blake Snell for his Sean Doolittle. Should I accept this deal?”

No. No you should not.

Blake Snell has been one of the finest starting pitchers in all of baseball this season. The Rays southpaw could even contend for the American League Cy Young at seasons end if he were on a different team. Snell carries an impressive 2.30 ERA and 3.30 FIP to go with a 9.73 K/9 and career best 13% swinging strike rate. There is nothing fluky about this performance. Opponents are chasing 32.7% of pitches outside of the strike zone. Snell's best pitch is his wipe out curveball, and the lefty decided to start throwing it more at the end of last season. He has carried that philosophy over into 2018, along with a change in the way he stands on the rubber, and the results have been fantastic.

Do not trade a significant asset like Snell for a closer, especially one as injury prone as Sean Doolittle. For the record, I am saying this is a poor decision for any closer. It would be a mistake to trade Snell for Craig Kimbrel. Would it be fair? Perhaps, but it would be a mistake nonetheless.

I would give this trade an: D

Rapid Fire:

"Thoughts on this trade? 14-team 5x5 H2H....give Altuve/Tanaka for Blackmon/Daniel Murphy/Bud Norris/Jankowski. My team leads in steals but I am lacking a bit in power."

You would be selling low on Altuve, whose power should come around at some point. If this happens, the upgrade in the power department would be minimal in the exchange. It would be worth the risk if you were maybe getting back a dependable option to replace Altuve at second base. Daniel Murphy is not that guy. Sure, this trade "could" work out very well for you. If Altuve's power outage continues and Daniel Murphy comes back from microfracture surgery healthy all season, this could be a decent trade. Those are big "ifs" though.

If you are looking to trade Altuve for power, why not go for Aaron Judge and get better supporting players back in the trade? Better yet, keep Altuve. Try and land Khris Davis. Krush is Giancarlo Stanton without the price tag. 40 home runs you can mark down in pen that will cost you a fraction of the cost of the reigning MVP.

I would give this trade an: C-

"Should I trade Travis Shaw and Justin Upton for Madison Bumgarner?"

No. No way. No. That is too much my friend. If you are trading for Madison Bumgarner today, the way he has looked so far, I would start by offering Justin Upton only. One for one. Let the owner counter that. You should not have to throw in much more at the moment.

I would give this trade an: D-

"Matt Olson, Bud Norris and Grienke for Kimbrel and Benintendi. Thoughts?"

I love this deal. Zack Grienke has a 3.87 ERA and 3.80 FIP while giving up a career high 44.7% hard contact rate. Give me Andrew Benintendi all day in this deal, who is on the verge of becoming a perennial second round pick in mixed leagues. The Boston outfielder boasts a .303/.390/.556 slash line with 12 home runs, 11 stolen bases, and a .399 wOBA. Benintendi has been caught in the shadow of his teammate Mookie Betts, but they are both amazing talents.

You then make a major upgrade as well going from Bud Norris (who I predict will not be closing much longer) for Craig Kimbrel. The loss of Matt Olson and his league-leading hard contact rate does not make up the difference in an otherwise fantastic trade. Great job.

I give this trade an: A+

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