As Hot Spots colleague Michael Street alluded to yesterday, BP will be finishing up Hot Spots for the 2010 season with a bright note, with fantasy baseball's surprises of the season. Again, these surprises will be based not only on judgment of the individual authors but also differences between projected values from before the season and their current 5×5 roto league value. The up-the-middle positions were ravaged with various injuries to key names, but quite a few players that were available in the waiver wires early in the year surprised more than a few people on the way to excellent seasons. To those of you lucky enough to have grabbed one of these names in the early parts of the season, I hope you're riding them to playoff victory now.

(Note: All preseason dollar predictions were taken from the Graphical Player 2010. All year-to-date dollar values were taken from Heater Magazine.)

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Kelly Johnson was presumed to be yesterday's news after being non-tendered by the Atlanta Braves despite having a year left in arbitration. After an awful season in which he was benched halfway through in favor of Martin Prado, Johnson seemed forgotten during the offseason. The Arizona Diamondbacks rightly took a chance on the 28-year old and struck gold. In 2008, Johnson hit .287/.349/.446, good for a .281 TAv and a bright future as the Braves second baseman. Two seasons later, even following the abysmal 2009 campaign, Johnson hit an even better .282/.365/.495 mark (.298 TAv) in the hitter's haven of Chase Field. His BABIP returned to around the same level he had posted in 2007-2008, and with it came the BA/OBP and some increased power. He busted out with 12 home runs through the month of May, and though he finished with 25, it was still a career-high mark. With the newfound power and regressed BABIP, Johnson beat his projected $2 auction value by $21 to date.

A lot of fantasy pundits were high on Johnson during the preseason, expecting a bounceback year, but not many could have claimed that he would have had this kind of success. Johnson is certainly due for some regression, and looking at his 2008 numbers shows exactly where that regression will start; his 2008 and 2010 rates are surprisingly similar, from BABIP to his slash line and even R and RBI totals, with one exception. Johnson's home run totals are sure to come down, even with added advantage of playing half of his games at Chase Field. The early hot streak he showed in April and May was followed by a tempered remainder of the season in the power department, with him only 13 HR the rest of the way. The good news for fantasy fans is that, even with reduced HR power (the preseason PECOTA 60th percentile forecast seems about right given this season's play), his high AVG and good walk rates should make sure he remains a valuable commodity going forward for fantasy owners. Be wary, however, of a trade away from Arizona, as the majority of Johnson's damage was done at home this season (.311/.396/.580 at home versus .251/.332/.404 on the road).

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Johnson's replacement in Atlanta, Martin Prado, is deserving of his own praise for an excellent season and a half as the Braves' starting second baseman, but his occasional replacement in 2010 is just as intriguing a case. Omar Infante started off in a super-sub bench role at the beginning of the season, but ended up receiving the call to action by May and has been playing more or less everyday since then. In response, he has posted the best season of his career, batting .326/.363/.422. Ironically, Infante made the All-Star Team amidst controversy despite having his best season as a pro. Infante's .326 AVG and consistent playing time has had him worth $19 this season based on Heater Magazine's estimates, far better than his $2 value prior to the season.

Infante is clearly not this good, but his time in Atlanta has certainly been a far cry from the rest of his career. After hitting an uninspiring .253/.298/.386 in 1732 PA as a Detroit Tiger, he has a hit a much more inspired .311/.354/.413 with the Braves. The difference isn't just in BABIP either, though that gap is fairly large (.293 as a Tiger, .345 as a Brave); he has also struck out a lot less (17.7% as a Tiger, 12.5% as a Brave), helping to boost that AVG further. Infante's power isn't likely to go anywhere, and he isn't as fast as his tiny physique makes him out to be, so much of his value is tied to AVG/OBP and playing time. RIght now, Infante is manning second base with Prado at third thanks to Chipper Jones' season-ending injury. With Jones' potential retirement looming, Infante could stand to be the beneficiary of such a move. A .290-.300 AVG is well within reach if he continues to strike out at the small rates that he has, and playing time will be plentiful if an infield spot is open. Add on the fact that Infante can play five of seven available non-catcher positions and that he will be just 29 in 2011 and the signs point towards a solid, if lower-valued, season for Infante next year.

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I've talked about John Buck in this space before, but it bears repeating; he has been this type of hitter for a while. Before, his low AVG due to high strikeout rates held im back fantasy-wise, but nothing like the lack of playing time in Kansas City did. Don't be surprised if Buck's 2011 slash line ends up looking a lot more like his 2009 line in limited playing time than his 2010 line with inflated BABIP. That .327 mark, a career-high, has helped Buck to a value of $17 in 2010, well above his preseason-projected $1 mark. Buck and whatever team signs him should expect 20+ HR with enough playing time, but a .240-.250 AVG is much more likely, and Buck will not help your rate stats if you play in an OBP league either. Essentially, it's home runs or bust with this backstop.

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I'm fairly happy to mention Ian Desmond here because he has been a Hot Spots staple all season long despite a fairly up-and-down 2010 campaign. Sure, Desmond does not apparently know how to draw a walk; 23 uintentional BB in 543 PA leads to an awful 4.2% BB%. And Desmond does lack power, getting extra bases on only 7.6% of PA and mustering only 10 HR. But what Desmond brings to the table is the potential for a solid .270+ AVG and good steal totals. He's not on base as often as you'd like, but when he is, he is willing to take off, running in 10.8% of basestealing opportunities this season. While he never showed the ability to take walks on a consistent basis (7.1% career BB% in minors), even a slight uptick in bases on balls should get Desmond on base often enough to pull off 20 steals. For a shortstop with a guarantee of full-time PT on a team with few other prospects at the position, Desmond stands a good chance of repeating or bettering the $17 estimated value he brought to 5×5 leagues this year.

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While Alex Gonzalez was never considered a journeyman, he sure traveled through a lot of different organizations during his time in the majors. A few seasons after winning a World Series with Florida, he ended up on the Red Sox (twice), Reds, and eventually the Blue Jays in 2010, where he decided to join in on the team-wide slugging phenomenon. The Jays slugger hit 17 HR in 348 PA, astonishing given that the most HR/600 PA he had ever averaged in a season was 23 in Florida in 2004. The Braves promptly dealt for the slugging shortstop, and he promptly cooled off, slugging .415 with a .159 ISO more reminiscent of his career .154 mark. While Gonzalez had maintained the correct batted ball profile for hitting home runs (48.7% FB% in Atlanta, compared to 46.7% career), his HR/FB% dropped to a more middling 6.2% from the 12.9% it was at in Toronto. That 6.2% mark is lower than his career 8.1% rate, but is far more representative of Gonzalez' power heading into 2011. Without that strong power, you are left with a career .245/.293/.403 hitter with no value on the bases and shortstop power.

The Braves are left with the decision to exercise Gonzalez' $2.5M club option or go with a potential internal option such as Diory Hernandez, with the possibility of moving Infante to shortstop if Chipper Jones returns, Those options and a struggling Gonzalez may make the Braves lean towards declining the option and sending Gonzalez back to free agency at age 34. Watch his movement and see if he ends up with a team with a hitter's park to call home; the last time he resided in a decent hitter's park for an entire season was in 2007, when he hit 16 HR and had his best offensive season for the Reds. Otherwise, expect Gonzalez to be a fantasy non-entity once again.

And with that, the Hot Spots section covering the up-the-middle positions wraps up. It has been a blast working on the Hot Spots column with Mikes Street and Petriello, Rob McQuown, and Bill Baer, along with the rest of the Baseball Prospectus Fantasy crew. I'd like to thank BP and John Burnson over at Heater Magazine for the opportunity to write for you BP readers, and I hope you all got as much out of these daily posts as we did writing them. I'm looking forward to get a chance to work with BP for the 2011 season as well!