When the Reds and Padres faced each other over the weekend at PETCO Park, it wasn't just a potential National League playoff matchup.

It was a meeting of two clubs that have been surprise additions to the stable of contenders. Although both clubs were expected to show progress this season, relative to their win totals from last year, neither was expected to be this good this quickly. But both clubs sowed the seeds for their success with surges in the final month of last season, and both entered this year with confidence that they could compete at a championship level.

"Last year, people realized that -- we're on a last-place team, but guys were going, 'Man, this team's like a first-place team, not a last-place team.'" Padres closer Heath Bell said. "It just seemed like we had a good core group of guys, the chemistry, the atmosphere was really good. At Spring Training, it just stayed the same. Everybody was working hard, everybody was coming together."

Despite a 3-6 start to this season, Bell said the club never lost its optimism. Instead, players buckled down and refused to panic.

"It was just like, 'Let's keep going,'" Bell said. "Before you know it, we start winning games, and it was just the morale, the chemistry, and how well we jelled together -- I felt like we're going to be good. We are pretty good."

Although not every losing team that gets hot in the final month of one season is primed to break out the next, clubs can blossom in the season's stretch run and parlay that success the next season. Look no further than the Reds and Padres for evidence of that -- Cincinnati went 19-11 in the final weeks of 2009, while San Diego finished the year with a 17-9 kick. The Astros and Orioles are showing signs this season of being candidates to make similar jumps, but both have stumbled over the past week, showing how difficult it can be to divine the future from a handful of games.

So how do clubs develop from an awkward adolescence into full-grown contenders? One expert said that it all starts with pitching.

"If you want to turn things around, it starts on the mound," said Dan Plesac, who spent 18 seasons as a big league pitcher and is now an analyst for MLB Network. "There are a lot of teams in baseball right now that can score runs, but there are a lot of teams that, the biggest flaws that you see, are in pitching."

The Padres are a prime example of the importance of pitching. San Diego's surge to the top of the standings in 2010 has been propelled in large part by its deep starting rotation and bullpen. The club has pedestrian offensive numbers, but the Friars finished the weekend ranked second in the NL in ERA and strikeouts and had allowed the second-smallest hit total.

"Other than Adrian Gonzalez, there isn't a lot of offense to speak of when you look at the Padres," Plesac said. "But they play in a ballpark that's really conducive to pitching, and the pitchers are confident right now, and I think that's why you see the turnaround."

Three Padres hurlers -- Kevin Correia, Clayton Richard and Wade LeBlanc -- pitched like aces last September. The trio has slotted behind Mat Latos, who has rapidly developed into a genuine ace, and Jon Garland, to form one of the best rotations in the league.

"I look at what's happening, and I see, especially with those young pitchers, that maybe they did benefit from that experience of having experienced both success and failure at the big league level and being able to apply that this year," said Geoff Young, who has written three books about the Padres and blogs about the club.

Young added, "There aren't a lot of teams that can legitimately go four and five deep in their rotation and not suffer too much for it at the back end, and I think the Padres have done a pretty good job of that this year."

The Reds' narrative has been a bit different. A number of young players saw increased playing time for Cincy and performed well offensively, including Joey Votto, Drew Stubbs and Jay Bruce. Plus, the club added third baseman Scott Rolen at last year's Trade Deadline. All of that combined to give the Reds reason for optimism entering this season.

Sure enough, the Reds' offense has been strong as it has clinched at least a share of the NL Central. The club leads the NL in average, homers and on-base percentage, with Votto, Bruce and Rolen leading the charge. But the team's pitching is in the middle of the league in ERA and toward the bottom in hits allowed and strikeouts. So what's been the key for the Reds? Justin Merry, who blogs about the club, said that the Reds' defense has been a significant component of its success.

"What makes this team so good is that on top of being a collection of really good hitters, they've also played really good defense," Merry said, adding, "The pitching is good -- it's not great. ... Fielding-wise, they've been spectacular, and I think that's a big part of the formula that's made them a good team."

Then again, just because a club has a hot month of September doesn't mean that it will be a guaranteed success the following year. Look no further than the Marlins and Angels, who were 19-12 and 19-13, respectively, in the 2009 stretch run but are both in third place this season. So who are clubs to watch for evidence that they're putting things together late this season? Keep an eye on the Astros and Orioles.

Houston left the gate this season with a miserable start that culminated with the club trading two of its cornerstones -- Astros general manager Ed Wade dealt hurler Roy Oswalt to the Phillies on July 29 and first baseman Lance Berkman to the Yankees on July 31. The Astros began play on Aug. 1 with a 45-59 record, and they showed signs of heating up by going 16-12 that month. The club then went on a scorching run to begin September, which was led in large part by its rotation; Houston won 12 of its first 17 games in the season's final month. But Houston gave some games back during the past week, going 2-5 on a road trip to Washington and Pittsburgh.

"So we're not the '27 Yankees, but we're not the team that was picked to lose 135 games, or whatever that number was. I'm sure it was a significant number," Wade said. "We've got work to do, and part of that work is to continue to give the kids a chance to play and sit down at the end of the season and everybody take a deep breath and step back. We love the enthusiasm. We love the approach."

The Orioles were also hot entering the season's final weeks. Baltimore went 16-10 in August after hiring manager Buck Showalter, then they began September with an 11-7 record. But the Orioles, too, have cooled a bit over the past week and exited the weekend on a four-game skid.

"We live in a 'What have you done for me lately,' an instant gratification society," Showalter said. "I just want the idea, whether its good or bad last night, you've got to be able to turn the page. But you also got to have a memory of why you are being a little bit more successful. I encourage guys to take notes ... something you can kind of revert back to when things go sideways."

Time will tell whether the Astros and Orioles were establishing a new level of excellence or on unsustainable hot streaks. That's the danger of measuring success based on a small sample of games.

"We don't have to worry about next year until Opening Day next year," Wade said. "We certainly have a greater body of evidence that these kids have the ability to play at this level, but we're not where we need to be. We're not pretending we're where we need to be or want to be, but I do think we're headed in the right direction."