What's up RotoBallers. Welcome back to my series on keeper leagues. Today I'll be taking a look at first basemen keeper values for fantasy baseball (tiers three and four) which include eight undrafted players and a veteran taken in the first round of 2016 drafts, for those of you deciding what players to keep for your teams.

Keeper Value Rankings are intended for Keeper Leagues in which a fantasy owner must forfeit a designated draft round in order to keep a player into the up-coming season. These rankings are based on Keeper "Values". In the marketing world, Value can be defined as: the extent to which a good or service (player) is perceived by its customer (fantasy owner) to meet his/her needs or wants.

For these specific rankings, 12 team, 5x5 scoring, 23 man roster, Rotisserie league settings were used. If you play in a custom league with non-standard configurations, are thinking of keeping a player not on this list, or want to compare players on your team, follow me on Twitter @RowdyRotoJB or contact me via the RotoBaller Chat Rooms.

Editor's note: Be sure to also check out our 2017 fantasy baseball rankings dashboard. It's already loaded up with tons of great rankings articles and draft analysis. Aside from our tiered staff rankings for every position, we also go deep on MLB prospect rankings, impact rookies for 2017, and dynasty/keeper rankings as well. Bookmark the page, and win your drafts.

How My Keeper Valuation Formula Works

The Keeper Values are derived from my 15 step Keeper Valuation Formula. The product is a quanitative depiction of a players ability to meet/exceed fantasy owners needs based on the cost they payed for the player in the previous season (2016 ADP). The higher the score, the higher the return the fantasy owner will receive from the player, keeping him at his associated cost. Approaching Keeper selections with this "value" based attitude, will greatly increase the effectiveness of a fantasy owner's draft in a Keeper League.

2017 Top First Basemen Keeper Values: #8-15

15. Justin Bour, MIA (23rd Round ADP) Keeper Valuation Formula Score: 1.44

As you can see, all but one of these first basemen were undrafted on average in 2016. Justin Bour was not an exception, but was still a popular low-end sleeper pick, heading into the season. The Marlin was certainly on his way to proving that to be true heading into July. In just three months he had racked up 15 HR, 46 RBI, and a .873 OPS. The excitement came to an immediate halt however, after a sprained ankle on July 2nd led to a stint on the 60 day DL. Bour finally returned in September, but was noticeably not in his first half form, and failed to hit another HR in his remaining 20 games.

Bour has legit left handed power. His 21.4 PA/HR ratio was very similar that of Anthony Rizzo, who hit 32 bombs over the full season. After posting an ISO of .218 and .211 in consecutive seasons, I have no doubt Bour can be a 30+ HR guy within the next few years. He is aided by impressive plate discipline, which reaped a 0.68 BB:K ratio that ranked top 10 among first basemen (with min. 300 PA), and was once again right on par with Anthony Rizzo.

The main concern with Bour, as is with many left handed power hitters, is his inability to hit southpaws. He owns a career .562 OPS and .068 ISO against LHP, which can continue to lower his fantasy potential. It is actually bad enough that the Marlins are considering this:

MLB Rumor Central: Marlins eyeing Chris Carter, Mark Reynolds? https://t.co/HOuYGyk0aR

— Sportsjunkie (@sportsjunkiemo) January 20, 2017

Last season's injury helps lower his draft stock in 2017, as he is currently projected as a 22nd round pick for 2017. Despite believing whole-heartedly that you would receive plenty of value from a late round keeper selection on Bour, I would not advise it if you can grab him later in the draft regardless.

14. Chris Carter, FA (23rd Round ADP) Keeper Valuation Formula Score: 12.02

After finished 2015 under the Mendoza line with only 24 HR, most fantasy owners had lost hope in Chris Carter. But the slugger rebounded in a huge way in 2016 in his first season with the Brew Crew. He was still his usual swing-and-miss self, with 206 SO (second highest in MLB), but he definitely found the power stroke as he smashed a career high 41 HR, and tied third in the league with an explosive .277 ISO.

Despite 40+ HR potential, Carter is far too risky to trust from season to season. His surprising 2016 campaign saw only a 0.6% total increase in contact at the plate from his abysmal 2015. While any improvement is a good thing, it is still concerning when just a little bad luck in the HR/FB department could transform a player from a 41 HR, .222 BA, 200+ K guy, back to a 24 HR, .199 BA, 200+ K guy. That is quite a leap in terms of fantasy value. Even if he lands on a stacked American League team (not the Miami Marlins...) don't waste a keeper selection here, especially if you are in a BA league or any points league that subtracts for strikeouts.

13. Miguel Cabrera, DET (First Round ADP) Keeper Valuation Formula Score: 15.58

The only man here that was not an undrafted free agent after fantasy drafts in 2016, Miggy kept the trust of fantasy owners after an 18 HR 2015 season, and repaid them nicely with his seventh consecutive All-Star performance. He did his usual thing at the plate, hitting over .300 for the eigth straight year, which makes 11 out of 14 in his career. The return of the power put many worries to bed, as he belted 38 HR, the most he's hit since 2013. Cabrera proved that age is far from catching up with him, as he ranked top 10 in the MLB in RBI (108) and OBP (.393), and top five in SLG (.563).

After posting the second highest wRC+ (179) over the second half of 2016, RotoBaller once again projects Miggy as a first round value heading into this season. Unless you have an early first round pick in your 2017 fantasy draft, you can keep Cabrera and still receive positive value, which is very rare. But then again, so is the ability to hit six bombs at once. But for Miggy, impossible is nothing.

12. Mike Napoli, FA (23rd Round ADP) Keeper Valuation Formula Score: 21.58

As he creeps over 35 years young, Napoli has settled into Chris Carter territory with his low contact but massive pop. He is a bit safer since we have seen the man hit over .300, even though that was now six years ago. He found himself in a great situation last season, landing with the American League winning Cleveland Indians, and Nappy loved every second of being in that offense. He set career highs in HR (34), R (92), and RBI (101) despite slashing a lowly .239/.335/.465. Napoli's bat just isnt quick enough these days  to catch up to fastballs, similar to what plagued Ryan Howard in his descent. Nappy ranked fourth in value against both curveballs and sliders (top heat map), and subsequently ranked fifth worst in all the land against the cheese (bottom heat map, four seam).

(FanGraphs.com)

I highly doubt Napoli lands on a team with a better offense than the one he enjoyed last season, but according to ESPN, Fox Sports, and MLB Network, the leading contenders for the veteran are the Rangers, Astros, and Mariners; all of which have plenty of offensive firepower to propel Nappy to fantasy relevance again in 2017.

11. Tommy Joseph, PHI (23rd Round ADP) Keeper Valuation Formula Score: 24.8

Tojo exploded onto the fantasy baseball scene during his rookie season in 2016 by smacking 21 HR with a monstrous .248 ISO, both ranked third among rookies, in 107 games after receiving the call up on May 13. If you think Bour has power potential over a full season, then Joseph says "Hold my beer." In fact, Joseph's PA:HR ratio (16.5) was actually better than Edwin Encarnacion who led the position with 42 HR. The kid can rake. But unfortunately, that is all he has shown the ability to do thus far.

Joseph has never been known to hit for a high average consistently, and seems to despise drawing walks (6.3 BB%). With the cap on the BA and OBP, that leaves counting stats for fantasy owners to grasp for to make his power worth drafting. Unfortunately for him, he plays on the Phillies, who havn't had a player reach 100 RBI since 2011. They are certainly on the rise with youngsters like Maikel Franco, Odubel Herrera and Aaron Altherr, and the acquisition of Michael Saunders this offseason. But they are far from being a reasonable offensive force in 2017, which likely means Tommy Joseph will be yet another option for cheap HR at the first base position.

10. Kendrys Morales, TOR (23rd Round ADP) Keeper Valuation Formula Score: 31.04*

Morales was a fantastic value in 2016, enjoying his second straight successful season at the plate with the Royals. He traded in some BA points in exchange for power this past year, reaching the 30 HR mark for the first time since 2009. His run scoring and production tailed off a bit as the Royals offense disappeared, but I have a strong feeling 2017 will be quite different as he joins a top ten ranked run-scoring Blue Jays lineup to try and fill the massive void left by the departure of Edwin Encarnacion.

I don't expect another 30 HR outburst from Morales in 2017, but getting his fair share of time in the heart of the Blue Jays order will present oodles of run scoring opportunities as he saw with the Royals in 2015. Unfortunately, as I'm sure you see the asterisk up by his score, only fantasy owners in Yahoo! leagues will be able to enjoy using Morales at first base this year due to their lax position eligibility requirements. If you are not playing on Yahoo!, I don't know why you are not anyways, I am sorry as keeping any player not named David Ortiz as a UTIL-only is not encouraged.

9. Greg Bird, NYY (23rd Round ADP) Keeper Valuation Formula Score: 35.35

Many fantasy owners were already excited about Bird heading into the 2016 season after he hit 11 HR in only 46 games following a late season call-up in 2015. But fans received the sad news prior to spring training that Bird would miss the season after having shoulder surgery. Fast forward to 2017 and the excitement is back as Bird is now recovered and slated to be the primary first baseman for the Bronx Bombers.

Bird Dog combined across multiple levels to hit at least 20 HR in three straight seasons prior to missing 2016. In his short big league exposure, he showed he hits a ton of flyballs (51.4%) and he hits them hard (44.8 Hard%). This will fit in perfectly to Yankee Stadium, which saw the highest park factor boost in HR in 2016, and has always been known to favor LHB. If Bird can work his way into the top half of the lineup with the likes of Brett Gardner, Jacoby Ellsbury, Gary Sanchez, and Matt Holliday, he should have a break-out campaign in 2017. I mean, look at those projections from RotoChamp out of the eighth spot. 

The experts at RotoBaller currently have Bird ranked at 187 overall heading into his first full season in the bigs. If you were smart enough to stash him last season in your keeper league, you found a good one.

8. Victor Martinez, DET (23rd Round ADP) Keeper Valuation Formula Score: 47.44*

Yet another first baseman that the majority of fantasy owners will not get to enjoy at the position in 2017, seriously people get in a Yahoo! league! After a monster 2014 season in which he finished second in MVP votes, V-Mart struggled mightily through an injury-plagued 2015. Many expected the then 37 year old to be reaching his stopping point, and it correlated to an extremely low draft status heading into last season. But Martinez burst out the gate and enjoyed a scortching hot first half in which he hit 17 HR and 52 RBI with a .305 BA. He cooled off considerably over the last stretch, but still finished with a 120 wRC+ that would've ranked right outside of the top 10 among first basemen.

Once again, if you play on Yahoo!, and you are in a "win now" mentality, Victor Martinez is certainly worth a keeper selection. If he does not have first base eligibility in your league or you are rebuilding, a 38 year old UTIL-only with a history of knee issues is probably not the direction you want to travel.

Keeper Value Articles: 

Catcher Rankings: Tier One

Catcher Rankings: Tier Two

Catcher Rankings: Tier Three