If any other team in the NL East had 10% more talent, the Mets probably wouldn’t be in first place right now. Through Wednesday, the Mets were on a pace to win just 90 games, which on the historical continuum of Mets winners puts them smack in the middle between the anemic 82–79 1973 team and last year’s 97-win club. If the Braves had a first baseman and another solid starting pitcher, if the Phillies had a real third baseman and a little more pitching, the Mets might be looking up at the competition instead of down. The opposition’s flaws are serious enough that they probably aren’t vulnerable to deadline day fixes, but the Mets aren’t yet safe. The way they’ve played of late, there may be worse yet to come.

Winning in baseball requires nothing more magical than scoring more runs than you allow. If, over a course of time, a team does this consistently, it will win consistently. If it more or less breaks even on runs scored or allowed its record will be in the vicinity of .500. Score fewer runs than you allow on a consistent basis and you’ll lose consistently. This isn’t particle physics or string theory.

Unfortunately for common sense but fortunately for the Mets, baseball has the same kind of “it works except when it doesn’t” exceptions that keeps string theory a bit less popular than the NHL. Over their last 30 games, the Mets have actually been outscored by their opponents but have posted a winning record anyway, going 16–14. This is due to the Mets winning the close ones, going 8–3 in one- and two-run games over that period while simultaneously dropping other games by bigger margins, such as their three-game sweep at the hands of the Rockies in the first week of this month, when they lost by scores of 6–2, 11–3, and 17–7.

While the pitching has slipped lately, its runs allowed per game rising from just a little over 4.00 to just a under 4.50, the offense has declined more dramatically. Over their last 30 games, the club is hitting more home runs per at bat than it had previously, but is still scoring fewer runs thanks to a decline in batting average and selectivity.

Based on runs scored and allowed, the expected winning percentage for the Mets over the last 30 games, and by extension, over the rest of the season should they remain in this mode, is .457. That’s a pace for 74 wins over a 162-game schedule and a 31–37 record over the rest of the season. The Mets could, of course, just keep defying the odds, winning because of the likes of Billy Wagner, Pedro Feliciano, and Joe Smith. More likely, though, if things don’t change, the team’s record will start to reflect what is actually happening on the field. As weak as the Braves are, the Mets won’t win the division with an 83–79 record. Willie Randolph isn’t Yogi Berra, and this isn’t 1973.

The good news for the Mets is that some problems could fix themselves. Moises Alou seems to be on the verge of the verge of returning. If he does, that should free the Mets to try Lastings Milledge as a permanent replacement for Shawn Green in right field. Though Milledge hasn’t hit much in his current return to the majors, it would be shocking if he couldn’t outdo the .220 AVG/.261 OBA/.330 SLG that Green has hit over the last 30 games, or the .239/.286/.365 he’s hit since May 1.

Similarly, the Mets will benefit when Carlos Beltran finally wakes up his bat (he’s hitting .143/.279/.321 in July), if he does. There is no alternative here, no better player that they can acquire or promote from within. The Mets will live and die with Beltran.

Catcher is a position where the solutions won’t present themselves just by sitting around and waiting. Paul Lo Duca has always been a player of great limitations. He’s not a great defensive backstop, and as a hitter without power or patience, he’s not an asset if he’s hitting less than .310. Outside of a torrid May in which he hit close to .400, Lo Duca hasn’t come close to a consistent .300 this year. In fact, he’s running hard in the opposite direction, batting just .214/.250/.321 since the end of May. In some ways, Lo Duca is doing the Mets a favor — had he put together a good year, the Mets might have been tempted to resign him at the end of the season, a move that would almost certainly have proved to be disastrous. With some odd exceptions, including Jorge Posada this year, old catchers do not hit .300 over full seasons. Lo Duca disclosing his future production to the Mets might cost them this year’s playoffs, but the price of re-signing him would almost certainly have been higher. That being said, the Mets do need to make a change. Ramon Castro can hit well when used selectively but would fade rapidly if used ever day.

The offensive struggles serve to underscore the importance of the team’s fifth starter, a position that will be relatively unimportant once the Mets reach the playoffs but could keep them from getting there now. Jorge Sosa has done a good job, albeit one unlikely to last. The Mets may soon be in a position to replace him with Pedro Martinez, leaving Omar Minaya to go after bigger fish, or more accurately, bigger bats.

Mr. Goldman writes the Pinstriped Bible for yesnetwork.comand is the author of “Forging Genius,” a biography of Casey Stengel.