The Oakland Athletics want a new ballpark. The team’s current home, the O.co Coliseum, is the only multi-sport stadium in use in Major League Baseball. The A’s share the Coliseum with the Oakland Raiders; in August, September and October, that often means football lines across the baseball field and diamond dirt on the gridiron. The conditions aren’t optimum for either team.

The Coliseum is also the fifth-oldest ballpark in the majors: only Fenway Park, Wrigley Field, Dodger Stadium and Angels Stadium are older. It opened for football in 1966 and for baseball in 1968, when the A’s moved west from Kansas City. Renovations in 1995 — when the Raiders moved back to Oakland from Los Angeles — favored football conditions at the expense of baseball. The most egregious example, of course, was the erection of Mt. Davis where the open outfield vistas once stood. Click here for photos of the Coliseum before and after Mt. Davis.

A’s owner Lew Wolff says the team needs a new ballpark to stay financially competitive with other teams in the league. Wolff has said the Coliseum simply lacks the kind of technology, amenities and corporate sponsorships common in most — if not all — other major-league ballparks. Earlier this month, Wolff told CNBC that a new ballpark could generate $100 million in additional revenue for the A’s. The details behind that figure aren’t clear; in particular, we don’t know how much of that additional revenue is expected to come from ticket sales, concession sales, merchandise sales, advertising and corporate sponsorships.

As a refresher, read this article I wrote in September, discussing the Athletics’ plan to move to San Jose and build a privately-financed ballpark in the downtown area, close to HP Pavillion, which is home to the National Hockey League’s San Jose Sharks. The San Francisco Giants oppose the move to San Jose, claiming they own the territorial rights to Santa Clara County, in which San Jose is the largest city. The dispute has been pending before commissioner Bud Selig going on three years now, and no end is in sight.

The proposed San Jose ballpark would be known as Cisco Field. This link includes architectural renderings of the new ballpark. The seating capacity at Cisco Field would be in the range of 32,000. As currently configured for baseball, the seating capacity at the Coliseum for A’s games is 35,067, with the upper deck seats covered in a semi-permanent tarp.

The A’s have been at or near the bottom of the league in attendance since 2008. The team hasn’t averaged more than 21,000 fans per game since 2007. Wolff points to the Coliseum as the reason fans stay away. Others argue Wolff’s single-minded focus on a new ballpark, the limited player payroll he gives general manager Billy Beane and the team’s losing record since 2006 have depressed fan enthusiasm and ticket sales.

So what can we glean from this season, when the A’s pulled off a near-miraculous division title in the American League West? Do this year’s attendance numbers tell us anything about how the A’s would fare in a new ballpark?

The A’s ended the season with the fourth-lowest overall attendance in the league (1,679,013), which was ahead of the Astros, Rays and Indians. Average attendance at the Coliseum was only 20,728. In fact, the A’s sold out only seven regular season games in 2012: Opening Day, the three-game series against the Giants in late June, the July 2 game against the Red Sox, the Sept/ 14 game against the Orioles and the last game of the season against the Rangers — when the A’s and Rangers were fighting for the American League West title. The A’s reached the 30,000-plus mark in attendance in only four other games: July 22 against the Yankees, Aug. 3 against the Blue Jays, Aug. 18 against the Indians (which celebrated the 10-year anniversary of Oakland’s 20-game winning streak) and the second-to-last game of the season against the Rangers.

Winning helped the A’s this year, although less than what might have been expected. Attendance increased by 14 %, with an additional 202,221 in ticket sales. The A’s did pack the Coliseum during the American League Division Series, with sellouts all three home games against the Tigers. Ticket sales for a possible American League Championship Series in Oakland were relatively brisk, enough so that the A’s decided to remove the upper deck tarps and sell tickets to an additional 11,698 seats at $55 per ticket. At that price, it would have been interesting to see how many of those upper-deck tickets the A’s could have sold.

Which is more important to attendance: a new ballpark or a winning team? Below is a table detailing the attendance figures and winning percentages for all teams with new ballparks since 2000. The table includes data for the year before the new park opened, the first year in the new park and the second year in the new park.

Team Attendance Last Yr/ OldPark Winning % Last Yr/ OldPark Attendance 1st Yr/ New Park Winning % 1st Yr/ New Park Attendance 2nd Yr/New Park Winning % 2nd Yr/ New Park Giants 2,028,399 .531 3,318,800 .599 (NL Wild Card) 3,311,958 .556 Tigers 2,026,441 .429 2,438,617 .488 1,921,305 .407 Astros 2,706,017 .599 (NL Central Title) 3,056,139 .444 2,904,277 .574 Brewers 1,573,621 .451 2,811,041 .420 1,969,153 .346 Pirates 1,748,908 .426 2,464,870 .383 1,784,998 .447 Reds 1,855,787 .481 2,355,259 .426 2,287,250 .469 Phillies 2,259,948 .531 3,250,092 .531 2,665,304 .543 Padres 2,030,084 .395 3,016,752 .537 2,869,787 .506 (NL West Title) Cardinals 3,538,988 .617 (NL Central Title) 3,407,104 .516 (NL Central Title) 3,552,180 .481 Nationals 1,943,812 .451 2,320,400 .366 1,817,226 .364 Yankees 4,298,655 .549 3,719,358 .636 (AL East Title) 3,765,807 .586 (ALWild Card) Mets 4,042,045 .549 3,168,571 .432 2,559,738 .488 Twins 2,416,239 .534 (AL Central Title) 3,223,640 .580 (AL Central Title) 3,168,116 .389 Marlins 1,520,562 .444 2,219,444 .426

Some key points:

The Cardinals, Yankees and Mets moved to ballparks with smaller seating capacities and saw attendance totals go down in the first year of the new ballparks, although all remained above the three-million mark.

The other teams also moved to parks with smaller seating capacities — except for the Marlins — and saw attendance totals rise in the first year. In the Marlins’ last season in SunLife Stadium, the capacity for baseball games was 36,331. The capacity for new Marlins Park is 37,000 — which essentially is the same.

Of the 13 teams for which we have second-year attendance figures, only seven teams saw attendance stay relatively stable in the second year. That includes the Yankees and Cardinals — the two teams that recorded attendance increases. Five of the seven teams with stable or increasing attendance had winning percentages greater than .500 in the second year. The exceptions were the Reds — which got close at .469, an improvement over the prior season’s .426 — and the Twins, which had an unexpectedly terrible 2011 season. The Twins attendance took a beating this year, the team’s third in Target Field, with a second consecutive losing season.

If this history is a guide, the A’s could reasonably expect to see an increase in attendance in the first year of a new ballpark, but will only maintain increased attendance by putting a winning team on the field. And this history comes with a caution sign for the A’s, as none of the teams with new ballparks since 2000 moved more than 40 miles from their old stadium, as the A’s propose to do. The A’s anticipate the move to San Jose would expand its fan base as it moves from a city with a population just shy of 400,000 to a city with a population just shy of one million. Whether the fan base simply shifts, without expanding, remains to be seen.

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A quick update on the lawsuit filed by a citizens group called Stand for San Jose, which wants to stop the city from selling downtown land to the A’s to build the ballpark: We reported in September that the city and the A’s filed a motion to force Stand for San Jose to provide sworn testimony and documents detailing the group’s membership in an attempt to show the group was just a front for the Giants and did not have city residents as its members. Last week, the judge presiding over the case denied the motion. The case will now proceed on the merits of the group’s claims that the city must first obtain voter approval before selling land to the A’s for the purpose of building a new ballpark.