Pitching is making a comeback -- but the question is: Why?

The Cubs-Sox game on Sunday night stood nil-nil through six -- that's hit totals, folks, not just runs. The duel between Ted Lilly and Gavin Floyd was the first game in 13 years in which both starters took a no-hitter into the seventh inning. But it was just another night on the pitch this season.

The Cubs won, 1-0. It was the 19th game this year in which only one run was scored -- on pace for the most 1-0 games since 1992.

What in the name of Mr. Fister (that would be Doug, he of the 2.45 ERA for Seattle, and not the soundalike '80s band) is going on in baseball? Pitchers have rolled back offense to early 1990s levels -- almost two decades, two expansions and a Steroid Era ago. Most key league indicators (runs per game, batting average, home runs) haven't been this low in a full season since 1992 or 1993.

(Standard disclaimer here: offense might always pick up in the hotter summer months -- except last year in the NL it didn't; it went down. So who knows?)

Here's what we do know: With about 40 percent of the season played, the rise of pitching has been the biggest storyline of the year. Already we have seen three no-hitters, including two perfect games, not including what should have been a third perfect game but for a blown call on the 27th out. We have seen Stephen Strasburg, 21, become the biggest drawing card in baseball and we have seen Jamie Moyer, 46, become the oldest man ever to throw a shutout. Ubaldo Jimenez (12-1, 1.16) is almost unbeatable. Roy Halladay, Matt Cain, Josh Johnson, David Price, Adam Wainwright.... OK, we get it, but.... Carlos Silva? Livan Hernandez? Jason Vargas?

This week began with 25 pitchers sporting an ERA under 3.00. No one expects that many to finish the season under 3.00, but here's some perspective: Last year only 11 pitchers went sub-three. In 2007 there was only one such pitcher. Suppose only 14 pitchers out of the current 25 finish the year below 3.00; that would still be the most since 1992.

It's not quite The Year of the Pitcher, not as long as we have 1968, which was for pitching what 1998 was for Winstrol. But it is The Year Pitching Returned. If it is a trend in baseball, of course, then it must be explained, and for the American-trained mind, the fewer explanations the better -- as in one. It's because steroids and greenies are banned! Well, life and baseball are not quite that simple. So here goes, an attempt to understand what's going on.

1. It's because steroids and greenies are banned! OK, this is a valid point if only because the better-playing-through-chemistry culture has been curtailed. Players who began their careers in the minors as long as nine years ago have been subject to drug-testing for virtually their entire pro careers. The pressure that was there in the 1990s for a young player to add bulk in order to hit home runs isn't there, so skills such as speed, defense and hitting for average have been re-valued.

But the major leagues began testing in 2003 and with firm penalties in 2006. And only now is the testing program depressing offense? And what, no pitchers were juicing back then? The PED cleanup is a factor, but not as great as you might think.

2. The Perfect Storm. Counting the pluperfect gem by Armando Galarraga, we saw three perfect games in 22 days. There were only two in the entire lifetime of John F. Kennedy. "A rash of perfect games" seemed as unimaginable an idea as "Marlins crowd." So cranking out one every week for three weeks gets our attention.

And the more attention we pay to these random, big events, the more we want to believe that something big is going on. And then we notice the near no-nos more, too. Starting on May 9, there were seven no-hitters or one-hitters in a 32-day span -- as many as occurred in the 2008 or 2009 seasons.

3. The state of hitting is awful. Batters strike out more than ever before and, anecdotally, there seem to be more defensive overshifts employed than ever before. A shift for J.D. Drew, a guy who has hit 30 homers once in his life?

The biggest problem with hitting, however, is the ineptitude of four teams: the Mariners, Astros, Orioles and Pirates. They are putrid. All four of those teams are scoring no better than 3.51 runs per game. We haven't seen one team that bad over a full season since the 1992 Dodgers -- and now four? The last time four teams were this bad over a full season? You have to go all the way back to 1972 -- before the DH existed.

Of course, maybe they'll get better. Or not. In any case, here is some perspective about how things have changed: the 2000 Phillies were the worst scoring team in baseball 10 years ago. Today they would be better than 11 teams.

4. Organizations are figuring out how to develop young pitchers. We like to make fun of pitch counts and specialized bullpens and such, but the fact is teams are much smarter about how they groom pitchers because of the availability and analysis of information. The idea of guarding against a Year-After Effect, which I have chronicled for about a decade -- basically, don't jump a young pitcher's workload by more than 30 innings a year -- is becoming an industry norm. (One GM told me his organization's annual pitching report includes a "VE" column, for Verducci Effect.)

Of the eight pitchers to throw a no-hitter or one-hitter this year, seven are in their 20s (Jimenez, Dallas Braden, Johnny Cueto, Mat Latos, Matt Cain, Galarraga and Jonathon Niese) and all but one of those seven is still pitching for his original organization (Galarraga).

Likewise, five of the top six ERAs in baseball belong to homegrown starters in their 20s (Jimenez, Jaime Garcia, Johnson, Cain and Price). And that group doesn't include established stars such as Tim Lincecum, Justin Verlander, Felix Hernandez, Clayton Kershaw, Yovani Gallardo, Jered Weaver, Zack Greinke and John Lester -- all homegrown success stories.

And then there is Strasburg, whose development began with coach Tony Gwynn at San Diego State. Strasburg's stuff and command are so good that he will have many more high-strikeout, low-hit games before the year is out. He has brought more focus to pitching. He is the greatest pitching phenom since Mark Prior in 2002-03, and in the company of Kerry Wood (1998), Dwight Gooden (1984), Fernando Valenzuela (1981), Mark Fidrych (1976) and Karl Spooner (1954). But none of those phenoms went on to Hall of Fame careers, and all offer cautionary tales:

• Prior exceeded 123 pitches 12 times in his first 52 starts (postseason included), including six times in his last nine starts of 2003, when the Cubs pushed him 67 innings beyond his previous threshold. He hasn't pitched since 2006 because of arm problems.

• Wood averaged 109 pitches per start at age 21, exceeding 120 pitches eight times -- and then broke down with arm trouble.

• Gooden averaged 257 innings a year from ages 19-21, then broke down with drug issues and arm problems.

• Valenzuela was 99-68 with a 2.94 ERA and 84 complete games in 200 starts from age 19 through 25 . Arm weary, he went 74-85 with a 4.25 ERA over the rest of his career.

• Fidrych threw 24 complete games in 29 starts as a 21-year-old rookie, suffered shoulder problems the next season and was never the same.

• Spooner threw 270 pitches in his first two games, both shutouts. He pitched one more season before he was finished due to arm problems.

None of that treatment would happen today. Given the informed manner in which he will be treated, Strasburg is nothing like those six.

5. It's cyclical. You don't want to hear this because it's not as fun as shouting across the bar, "It's because steroids and greenies are banned!" But this one is not only true, it's also the most practical explanation. Why are DHs hard to find? Why is the Golden Age of Shortstops over? The supply of talent at positions does not flow in a steady, even stream any more than world economies. Boom times are prelude to recessions, which are prelude to booms.

A great generation of aces aged and washed out of the game in recent years, including pitchers such as Roger Clemens, Randy Johnson, Greg Maddux, Tom Glavine, John Smoltz, Mike Mussina, Pedro Martinez and Curt Schilling. Behind them came the recession, with few potential Hall of Famers. But this generation of 20-something pitchers looks like another boom. The good news, if you like pitching, is that the boom only has just begun.

But if you are a major league owner, you might not be so enthralled with what this year portends. Outside of the rare phenom like Strasburg, pitching doesn't sell. Attendance is down three percent this year, and that's coming off a down year last year. Across general baseball history, spikes in attendance have dovetailed with planned spikes in offense (introduction of the live ball, the lowering of the mound, the DH, expansion, smaller ballpark boom, etc.).

Like it or not, though, pitching is the story of the season.

COCORAN:Examining other pitching-dominated seasons

GALLERY:Best pitching performances of the season

MARCHMAN:Breaking down Ubaldo Jimenez's historic stretch