This April, I wrote a column in which I averred that Barry Bonds was basically done as a great hitter, citing the effect of his various knee problems on his ability to run and, far more important, his ability to generate bat speed. At the time, he was hitting .167 and was barely able to jog down to first base; my suspicion (shared by many) was that he would keep drawing his walks until pitchers figured out that he couldn’t whip the bat the same way he once did, at which point he’d be completely exposed as a crippled shell of a player.

Several months later, having passed Babe Ruth on the all-time home run leaderboard and been the subject of reports that he was about to be indicted for perjury and tax evasion, Bonds has shown that he is indeed a shell of the player he once was — and still one of the 10 best hitters in the National League. I, and many others, underestimated a player who for all his grave flaws is still probably the greatest of all time.

Leaving aside the various issues surrounding him, people thought Bonds was done for a simple reason: He looked done. Further, there was little reason to think that in this case looks were deceptive. Forty-two-year-old athletes who have just missed a year due to knee surgery and various post-operation infections, and who then prove unable to stand for lengthy amounts of time, generally are done.

Bonds’s numbers are certainly down quite a lot. In 2004, he hit .362 BA/.609 OBA/.812 SLG, with 129 runs, 45 home runs, and 101 runs batted in. This year, he’s hit .263/.459/.543, with 68 runs, 24 homers, and 67 RBI.It’s a huge decline — but only relatively. Because Bonds takes off quite a few games and because he walks so much, he’s the player in the game whose offensive value is least well represented by his batting average, home runs, and RBI, and even to some extent by his on-base average and slugging percentage. Those latter two statistics are viewed through the prism of the PlayStation-like numbers he was putting up a few years ago; the truth is of course that an OBAheavy OPS of 1.010 would be a career year even for most great ballplayers.

Look at more advanced measures and the point becomes more plain. Baseball Prospectus has a statistic that measures how many runs per plate appearance a player contributes above those a AAAA type like Michael Tucker would contribute — Bonds is eighth in the league. Fangraphs.com tracks how many wins a player contributes above average taking game situations into account, thus counting the bottom-of-the-ninth walk-off shot as much more valuable than a home run that raises the lead from eight to nine runs. Bonds is tied with Lance Berkman for sixth place.

There isn’t even much reason to think Bonds is done in the field. He certainly looks slow and horrible, but by every available measure he’s still getting to balls in left field.

I don’t much regret thinking that Bonds was finished; to think otherwise would have required a leap of faith. On the other hand, it might have been better to hold off making the judgment at all. Knee injury or not, Bonds is not the typical 42-year-old athlete, and he’s made the necessary adjustments to keep his stroke fast and compact while staying healthy enough to play as often as possible, and so improved during the season. Over the last six weeks he’s stroked 10 home runs and seven doubles while scoring 22 runs in 99 at-bats, his best run of the season.

All this reminds one that he is, after all, a free agent at the end of this season, and while it seems somewhat inconceivable that he would pass Hank Aaron anywhere else but in San Francisco, it would have seemed quite inconceivable a couple of years ago that Greg Maddux would be a Dodger and Frank Thomas an Athletic right now. Things change, and between their aging team, Bonds’s various scandals, his still-questionable health, and the possibility that negotiations will simply break down, it’s no sure bet he’ll return as a Giant next year. Look at Roger Clemens’s various imbroglios with the Astros for an example of how even two parties who want to strike a deal can find it difficult to do so when dealing with an athlete who’s just too old to be relied on and yet still ranks as one of the very elite in the game.

Were he to go elsewhere, it’s hard to imagine Bonds as anything other than an Athletic, and not just because of Oakland’s proximity to San Francisco. The team has long welcomed aged, controversial black players, from Dave Parker to Rickey Henderson to Thomas, perhaps because of its laidback culture and the relative quiet and isolation of Oakland itself, which is hardly an intimidating media market. Really, though, who knows — maybe he’ll end up a Yankee or a Royal.

Whatever happens, Bonds is almost certainly going to be vastly underpaid, as he was during the seemingly ridiculous deal now expiring, which paid him $22 million a year. We can keep writing him off, we can expect him to be indicted, and all the rest, but the truth is that when a player is so good that in his deepest decline he hits like Lance Berkman, it’s impossible to overstate how good he really is.

tmarchman@nysun.com