by Adam McClavy, MLB.com

This season more than ever, Miller Park has been the Brewers’ dome, sweet dome.

Rainouts are all the rage in Major League Baseball, 31 of them in a baseball season not one-third complete. At the same time last year, there were nine postponements. In all of 2010, there were only 21.

According to data provided by the Commissioner’s Office, from 2000-2010 the previous record for postponements through May 25 was 30, set in 2007, the year an Angels-Indians series was moved to Miller Park because of snow in Cleveland. The record for postponements in a season over that 11-year span is 50, set in 2004.

Albert Pujols might be slumping, but Mother Nature is working on a career year.

Even when games have been played this season, many have been miserable. In Arlington earlier this week, a Rangers-White Sox game was delayed nearly three hours by a dangerous storm that prompted Rangers officials to move fans into the service tunnel underneath the ballpark. The game eventually resumed, but didn’t end until 1:27 a.m. CT.

Ninety miles south of Milwaukee, fans at Wrigley Field shivered through mid-40s temperatures this week, and on Thursday afternoon they were greeted by a 30-mph wind blowing in during the Mets-Cubs game.

At Miller Park, under its 10.5 acre, 12,000-ton convertible roof, the weather has been just perfect.

“I know this was a big part of the stadium debate, and I know it added to the cost,” Brewers chief operating officer Rick Schlesinger said. “But I don’t see how anyone can look at this now and say the roof wasn’t a great idea.”

The roof does have something of a stormy history. Three iron workers — Jeff Wischer, William DeGrave and Jerome Starr — were killed in July 1999 when a huge crane collapsed in high winds at the Miller Park construction site. The accident delayed the ballpark’s debut until 2001, and since then, crews have had to fix the system of flaps that keep the playing surface dry. During the 2006-07 offseason, crews replaced the bogeys with which the five massive, movable panels open and close.

But on an otherwise miserable Wednesday in Milwaukee, Zack Greinke pitched and homered his way to a sweep-clinching win over the Nationals inside the dome, and the Brewers were happy to have a roof over their heads.

Here are three reasons why:

1. It’s good for the pitchers

Pitching coach Rick Kranitz had the same job with the Florida Marlins in 2006, when right-hander Josh Johnson was a promising rookie with a 12-7 record and a 3.10 ERA. Johnson’s season ended Sept. 12, and Mother Nature may have been partly to blame.

Johnson resumed pitching after an 82-minute delay but exited after the fifth inning with a sore elbow. Less than a year later, he needed Tommy John surgery, and it wasn’t until 2009 that he logged a full season in the big leagues and emerged as an ace.

“You never know what triggers it when a guy gets hurt, but you can’t rule out that it was because he stopped and then [came back] and pitched,” Kranitz said.

Johnson represents the extreme case. But even a routine rain delay can wreak havoc on a pitching staff.

Shaun Marcum has made most of his starts in domes, with Toronto from 2005-10 and now with Milwaukee. In May 2008, he was part of a manager’s worst-case scenario, a game that begins, lasts only one inning and then is delayed by rain.

Marcum pitched the first inning that day, and then he was done. The Blue Jays had to empty their bullpen.

“I’ve been blessed to have a dome in both places,” said Marcum, who will start Friday night against Tim Lincecum and the Giants. “As players, you love that feeling of knowing you’re going to play. We have so few off-days, and you hate to lose them later in the season [when make-up games are scheduled].”

Kranitz knows that feeling from his two seasons as the pitching coach in Florida, where rain is a threat nearly every afternoon. The good thing there, he said, was that the weather forecasts were so precise he could plan accordingly. It was tougher in Chicago, where Kranitz was an assistant pitching coach for the Cubs from 1996-98 and 2000-01.

Each day, he would look up at the skies to see what his pitcher would be contending with. The conditions would help determine the game plan.

Not at Miller Park.

“When this is what you do for a living, it’s huge to know you’re going to play every day, you’re not going to have rain delays and the conditions are going to be about the same,” Kranitz said. “You can get into your routine every day and know you’re going to play. We have it good here.”

2. It’s good for the hitters

Ryan Braun had 105 million reasons to sign a contract extension last month that will keep him in a Brewers uniform through at least 2020. But beyond the dollars, Braun pointed to the ballpark itself as a reason he wanted to stay.

“This past road trip,” he said then, referring to a soggy trek through Pittsburgh, Washington and Philadelphia, “we dealt with rain almost every day, and I think that realizing that we’re never going to get rained out or have a rain delay, fans not having to worry about driving three hours and then dealing with a rainout and having to drive back home [is important]. There are so many things here that just really make this a special place.”

The dome means that if the Brewers want to take batting practice on the field, they can take batting practice on the field. During that East Coast trip, they were mostly banished to the batting cages.

It also means favorable in-game conditions, unlike the days at County Stadium, where Robin Yount, Paul Molitor and Gorman Thomas had to bundle up in April and sometimes in May. The chilly early-season conditions were part of what made County Stadium a pitcher’s park, but Miller Park most definitely favors the hitters.

The Brewers have baseball’s best home batting average at .291 and the best OPS at .860. It’s one reason the team is 19-6 at home this season, the best mark in the National League.

Braun & Co. will put a nine-game home winning streak to the test on Friday night against Lincecum and the World Series champion Giants.

3. It’s good for business

General manager Doug Melvin uses Miller Park to draw players, touting the roof in a letter he sends to free agents of interest each winter. Schlesinger uses it to draw fans, and he is still bullish on the idea of reaching the three-million mark in attendance in 2011.

Group sales account for about 600,000 tickets each season, Schlesinger said, and the Brewers consistently rank in baseball’s top five in that category. They can outdraw much larger metropolitan markets because guaranteed games mean the club can market itself throughout Wisconsin, and school kids in La Crosse or a civic group in Green Bay can bus to Milwaukee knowing they won’t be rained out.

Schlesinger calls it, “a huge advantage.” Braun just calls it fun.

“To be in one of the smallest markets in baseball and be able to have three million people come see us play every year, it’s incredible,” Braun said. “It’s special to me, it’s special to all of us and it makes it easy for me to want to stay here and to want to be a part of this organization going forward for the rest of my career.”

If Schlesinger had his way, every stadium would have a roof. The Brewers benefit from large crowds in the other 29 markets because they are a recipient of revenue sharing dollars.

Rainouts cost those teams in the form of lost concession revenue and staffing in addition to tickets. All told, a rainout of a well-attended weekend game can cost a club $1 million, Schlesinger said.

“We could have had four, five, six rainouts already, and some of those games are never made up,” Schlesinger said. “Without the roof, it’s a much different business model for us, a much bigger challenge.

“[Weather] makes for added stress for everybody. We are so privileged not to have to worry about it.”