One of the most unique aspects of spring training is the uncanny match-ups, which makes you wonder if the idea behind regular season inter-league play was first conjured up here. But in 2010, spring training will be particularly unique in quite another way as well.

The Reds’ move from Florida to Arizona for 2010 means there are 15 teams training in each state, resulting in MLB getting a major case of the split-squad. In case you’re not familiar, whenever you see “ss” on a spring training schedule it means a club has split its squad into two teams for that day’s games. Typically, one team plays at home while the other squad plays an away game. To fans, the split-squad game can often be a bummer, with some of their favorites not suiting up (depending on where they’re playing).

But split-squad on steroids has become a necessity because of the uneven number of teams now training in Arizona and Florida. For example, 22 of the 32 dates on the Cactus League calendar will feature at least one split-squad game with seven of the 10 games on March 20 featuring split-squads. In the Cactus circuit, only the Rangers are spared multiple split-squads whereas the 14 other clubs will play at least two dates. The Athletics have the most split-squad dates on the ledger with four followed by the Rockies, Dodgers, Giants, Padres and Cubs with three each.

In Florida, 22 of the 33 dates on the Grapefruit League docket feature split-squad affairs, with eight split-squads competing on March 21 alone, affecting six of the 10 games scheduled. The Blue Jays, Orioles, Braves, Phillies and Cardinals have only one split-squad day while the Yankees, Red Sox and Tigers have four each.

Interactive AP Get maps, info on every spring training site: Arizona  |  Florida

Solution to Holy Split-Squad? None appears likely in the following two seasons with most teams locked into long-term lease agreements with their spring training host cities. But an interesting club to watch is Milwaukee, whose current lease in Phoenix ends following the 2012 spring training. The Brewers have never trained in Florida but they’ve also never drawn well in Arizona, and the team wants renovations made to its Maryvale Complex as part of any renegotiated lease. The Astros have never flourished in Florida, but their lease doesn’t expire until 2016. So don’t be surprised if two Florida cities make overtures to the beer makers — Vero Beach, former spring home of the Dodgers, and Naples, which recently made a valiant run at luring the Cubs before the lovable losers decided they’d stay in Arizona.

Now let’s take an inside look at some of the interesting match-ups and rare nuggets of what makes the Cactus League and Grapefruit League tick:

ARIZONA: THE CACTUS LEAGUE
With the Reds joining the Cactus League in 2010 and sharing the same Goodyear complex as the Indians, there are several intriguing inter-league match-ups, starting with Buckeye State pre-season bragging rights as the two Ohio teams tussle multiple times. Other annual spring rivalry games include the Bay Bridge Series (Oakland-San Francisco); Windy City Series (Cubs-White Sox); and Freeway Series (Dodgers-Angels).

Most interesting is that as teams like the Dodgers, Indians and Reds have relocated to Arizona in recent years, fans get a sneak peak at how the regular season might unfold with several divisional match-ups. In 2009, for example, the Dodgers became the last National League West team to relocate its spring training to the Grand Canyon State, which means annual exhibition games now against arch rival San Francisco, and lesser rival San Diego. Rest assured players and coaches aren’t slouching in spring, instead studying the detailed tendencies of hitters and pitchers of their division rivals closely.

The Indians now hook horns with American League Central foes Chicago and Kansas City while the Reds will soon face National League Central clubs, the Cubs and Brewers, for the first time in Arizona. The rare, six-team National League Central is decidedly a split decision, with the division’s three other clubs — Houston, St. Louis and Pittsburgh — all training in Florida.

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The states of Texas and Missouri are also split in half, with the AL Rangers in Arizona and the NL Astros in Florida, and the AL Royals in the desert while the NL Redbirds bask in the Sunshine State.

Other rare Cactus League nuggets:

• With the Reds sharing the Goodyear complex with the Indians starting this spring, the Padres-Mariners dual-use complex relationship — both are also inter-league rivals — remains the only one in MLB where at least one dual-use spring training complex has yet to be home to a World Series winner (the others that have at least one World Series victor: Marlins-Cardinals; Rangers-Royals; Dodgers-White Sox; and Reds-Indians);
• With the exception of the Rockies and Diamondbacks training within three miles of each other in Tucson, the Angels and Giants not only are the two sites closest to each other in Arizona, but every year it’s a chance to see the two California clubs that played in the 2002 Fall Classic; they’re not the only ones, however. In addition to the A’s-Giants (1989 World Series), the Dodgers-A’s (1988 World Series) also get together, and with the Reds arrival in the desert, a 1990 championship rematch gets rekindled with Oakland;
• The Brewers (formerly the Seattle Pilots — remember them?) often play the Mariners, an MLB expansion team while Oakland (formerly the Kansas City Athletics) take on the Royals, another expansion team;
• With the Indians rejoining the Cactus League in 2009, it rekindled their opportunity to play against the Giants; both began playing one another in Arizona in 1947 and were members of the inaugural Cactus League in 1954 when the Cubs and Orioles planted in the desert;
• 2010 is the final year for the Diamondbacks and Rockies in Tucson — and probably MLB spring training in general in Old Pueblo; both clubs are slated to open a new dual-use facility outside Scottsdale next spring;
• Tucson spring training might actually have died altogether in the early 1990s were it not for the expansion Rockies joining MLB and training there since 1993;
• Cactus League action has not only all the NL West teams, but also all the AL West clubs, offering a preview of what’s to come in both divisions;
• Curse for the worst? The Cubs spring home, HoHoKam Park, is right across the street from a cemetery. It will be interesting to see where the new ballpark in Mesa will be built for the loveable losers when it opens in a few years;
• The Rockies and Brewers have the highest percentage of male fans (74 percent) while the Angels have the greatest percentage of female fans (48 percent) — and also the youngest fans, with the average Halo fan attending spring training games 36 years old.
• With the Reds' move to the desert in 2010, it marks the fifth team east of the Mississippi to train west of the famous river. The Indians, White Sox, Brewers and the Cubs are the other four clubs.