What's up RotoBallers. Welcome back to my series on keeper leagues. Today I'll be taking a look at third basemen keeper values for fantasy baseball (tier two)  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 Third Basemen Keeper Values: #4-7

7. Kyle Seager, SEA (Seventh Round ADP) Keeper Valuation Formula Score: 51.95

For the sixth consecutive season, Kyle Seager has again improved his statistics at the plate. Seager often flies under the radar in fantasy due to third base being such a lucious position, but Seager has in fact been the 12th best player in the league over the past four seasons according to WAR. As was 2015, and 2014, 2016 was a career season for the third baseman. He set career highs in R (89), HR (30), RBI (99), BA (.278), OBP (.359), and of course SLG too (.499). He has now joined Robinson Cano, Josh Donaldson, Mike Trout, and Paul Goldschmidt as the only players in the league to hit at least 30 doubles and 20 HR in each of the past five seasons. He hit the ball harder than ever before (38.7 Hard%), he hit the ball to the opposite field more than ever (28.3 Oppo%), anything you want a hitter to do well, Seager did it in 2016.

Kyle Seager has grown into a foundation-level player for the #Mariners | @RyanDivish explains >> https://t.co/4HBhTd25KO pic.twitter.com/CQMjUFfx4j

— Seattle Times Sports (@SeaTimesSports) February 6, 2017

Not only is Seager constantly maturing at the plate, but he is also becoming an absolute gem in the field. His 15 defensive runs saved in 2016 tied him with Adrian Beltre for second best among third baseman. As if this all wasn't impressive enough, the dude is DURABLE. Last season he played more innings at the hot corner than any other player in the league, and since 2012, only Robinson Cano has played in more MLB games than Seager. He has it all.

We could look at BABIP and HR/FB% and try to project where Seager could suffer regression, and blah blah blah. But career average comparisons don't mean squat if the hitter goes out and bests his previous self every season. If you are going to project Seager's 2017 stats, I suggest you start with last season as a baseline and work your way up. He hasn't shown that he is done growing as a hitter, and history tells us you'd be wrong otherwise.

6. Justin Turner, LAD (18th Round ADP) Keeper Valuation Formula Score: 66.08

It's quite amazing what a full season of at bats will do for a ginger. Justin Turner, a seventh round pick by the Reds in 2006, finally received that opportunity in 2016 and played a career high 151 games. After playing every infield position for the Dodgers in 2015, and having a solid year at the plate, Turner was rewarded with the starting role at the hot corner. It did not start off very well. Through June 6th, Turner was hitting .233 and slugging a measly .326 with three HR. But then, the breakout commenced.

I noticed at the All-Star break as Turner strolled in as the 25th ranked third baseman, that his numbers were far too low and made this bold prediction that he would finish as a top 10 fantasy third baseman. He did not quite make it in the fantasy rankings, but he still hit .298/.349/.549 in his last 65 games with a .251 ISO and 141 wRC+. He finished the season with a 124 wRC+ that actually tied Arenado for seventh best at the position, so technically I was right. The 31 year olds final stat line was .275/.339/.493 with 79 R, 27 HR, and 90 RBI.

2016 was Turners first season with a GB/FB ratio under 1.00, and he hit a career high 37.6 Hard%, so the power output is understandable. He achieved these results by feasting on offspeed pitches. He owned the second best wSL (10.8) and eighth best wCB (7.1) in the league. Here is the SLG heat map comparisons between fastballs and offspeed pitches:

Turner's 2016 is a very solid projection for what he will produce in 2017 if he can avoid the early season woes. He hits third in the Dodgers lineup sandwiched between Corey Seager and Adrian Gonzalez so the counting stats will be plentiful. Rotoballer agrees with me, and has him ranked as a sixth round pick in the pre-season rankings.

5. Nolan Arenado, COL (First Round ADP) Keeper Valuation Formula Score: 70.33

Over the past two seasons Arenado has averaged 41.5 HR, .573 SLG, and .286 ISO. He has led the NL and HR and the MLB in RBI in both seasons. In 2016, he played in a career high 160 games, and the career high batting statistics came flowing in. He scored a personal best 116 R, while setting a new high .294 BA and .362 OBP. He made great strides in his plate discipline, almost doubling his career BB% and cutting down on his swings outside the strikezone by more than six percent. He finished the 2016 season as the only player in the MLB to score 100 R, hit 40 HR, and knock in 100 RBI.

This guy is an absolute monster. He set career highs with a 46.7 flyball percentage (sixth highest in the league) and 37.9 hard hit percentage, with both stats increasing every season since 2013. Arenado is a big time pull hitter, pulling the ball at a 45.7% rate, which works out perfectly for the power. When hitting the ball to leftfield last season, he hit 34 of his 41 bombs with the second highest pull ISO in the league. It goes without mentioning that Coors Field greatly enhances the long ball, and while Arenado did defy all odds last season by  hitting more HR away than at home, in 2016 he drank the cool-aid. At Coors, he hit 25 HR and 85 RBI with a 1.030 OPS and .334 ISO versus 16 HR and 48 RBI with a .832 OPS and .215 ISO. As you can see it was fairly drastic, but fantasy owners never complain when a hitter takes full advantage of that Colorado air.

As I've said before, it is extremely difficult for a player to produce a strong score from the Keeper Valuation Formula with a first round draft pick. Usually it just makes more sense to release your big fish and try your luck at drafting him again in the first round the upcoming season. But with a player who has become so elite in fantasy such as Nolan Arenado, it is not wise to ever let go. Have you seen the Rockies lineup this year? 116 R and 133 RBI are childs play compared to what this man can produce in 2017.

4. Jake Lamb, ARI (23rd Round ADP) Keeper Valuation Formula Score: 72.53

How's about another breakout season? In Lamb's first full year in the bigs, he finished with a powerful 81 R, 29 HR, 91 RBI and .249/.332/.509 for the Diamondbacks. He was also 6-7 on the basepaths. He increased his BB% to 10.8, and more than doubled his 2015 ISO to .260. Lamb came out of the gate like a bat out of hell, owning the second highest ISO and SLG for the first half of the season with a 41.9 Hard%. But he also owned the leagues highest HR/FB% at the break, and it didn't take a genius to know that wasn't going to last forever.

The 26 year old went on to own the third lowest WAR in the entire league over the second half of the season, but I'm going to chalk that up to first-full-season fatigue. Besides, that was not the only troublesome split to worry Jake Lamb owners from 2016. He also struggled away from Chase Field, a.k.a Coors Field Jr, as it finished right behind Coors as the second highest run producing park and right in front of it as the second highest HR heavy park. For the season, Lamb hit .231 with only 10 HR Away, with an OPS that was 200 points less than his home mark. The third baseman also struggled mightily against lefties, hitting a sad .164 BA, which was even five points lower than his (brief) career average.

Despite all the question marks revolving Lamb heading into 2017 fantasy drafts, there is no questioning his ability to put the ball in the stands. His low line drive percentages and high strike out rate (25.9 K%) will ensure the BA never gets high enough to benefit your lineup, but the power can play in any league. His draft status from 2016 is the real driving force behind his stellar keeper value score, but if you want to free up your early round draft picks by keeping a potential stud in the later rounds, Lamb is your man. The dude can RAKE against RHP, and in daily roster moves leagues, that can carry serious value.

 
RotoBaller pre-season rankings slot Lamb as an eighth round value in 2017.

Keeper Value Articles: 

Catcher Rankings: Tier 1

Catcher Rankings: Tier 2

Catcher Rankings: Tier 3

First Base Rankings: Tier 1

First Base Rankings: Tier 2

First Base Rankings: Tiers 3-4

Second Base Rankings: Tier 1

Second Base Rankings: Tier 2

Second Base Rankings: Tier 3

Third Base Rankings: Tier 3