They apparently didn't, at least not according to historians who study Chancellorsville. Both Bigelow and Sears state about 800 casualties on May 2.
You clearly have trouble differentiating between tactical and strategic victories. Chancellorsville was a clear Confederate tactical victory but a limited strategic win since the armies ended up pretty much where they were before Hooker began his campaign.
Ryan
Thank you Ryan . Here is a way to get you out of the thinking that doomed Lee.
There is a sense in which the number of battles won is irrelevant, if the victor in them hasn't also won the war. The US experience in Vietnam is relevant here. That said, it's not always easy to say whether a battle is a "victory". How do you judge? There are several criteria often used:
Who remained in possession of the battlefield at the end of the battle?
Which side suffered the higher casualties? By absolute numbers? Or as a percentage of forces engaged?
Which side advanced its war aims, or at least campaign objectives, by the battle?
If you focus on the first criterion, Lee scored a number of "victories" during his one good year, from June 1862 to May 1863, and even during the Overland Campaign in 1864, when there were days when Lee's defending army inflicted higher casualties on Grant's army than Lee's army suffered. More often than not, though even when Lee "won" a battle, it suffered more casualties, absolutely or by percentages, than its opponents. And Lee himself lamented that his "victories" never seemed to have any positive effect beyond the day of battle. If you go by casualties, Lee's "box score" declines steeply compared to judging solely by possession of the battlefield. If you go by whether a battle advanced war aims or campaign objectives, it could be said that Lee lost every battle he fought, though to be fair one could also say Lee's aim was to drag out the war, and at that he succeeded. If that's your argument, though, you should ask "To what end?", and no matter what the purpose, Lee didn't accomplish it.
I haven't personally tried to count wins and losses because the criteria are so debatable. I have read one historian arguing that Lee fought 26 battles and won 13. I think that gives Lee too much credit, given his horrendous casualty rate and wasted efforts, but if your goal is to praise Lee, you might seize upon any argument, however specious, that makes Lee look good.
Grant presents a different debate. With the exception of Shiloh, Grant only fought battles as part of campaigns in which he decided whether to seek battle or not, accepted a battle only when he considered it worthwhile, and even so didn't expect to win every single time. Even at Shiloh, Grant pulled out a victory on the second day, but the fight was a mistake on his part. He later regretted the attack at Cold Harbor, which accomplished nothing except great slaughter of his troops. Generally, though, Grant didn't fight battles unless he had to, and only then as parts of campaigns adapted to well-understood strategic war aims, and he never lost a campaign. He had a few days when his troops suffered more casualties than their opponents, but only a few. Grant had a better win/loss percentage than Lee by any criterion.
In just under 30 months of active field command, Lee suffered 209,000 combat casualties, about 7000/month, and accomplished nothing except slaughter and delay of the ultimate rebel defeat. In 42 months of active field command, Grant conquered huge swaths of territory, compelled the surrender of three rebel field armies, opened all the western rivers to US navigation and commerce, cut the south off from the salt, beef, hogs, mules, and grain of the west, positioned Sherman's army to fall upon Atlanta and then sweep through the rest of the southern logistical base, came east and pounded Lee's army into entrenchments, and won the war. Under the circumstances, a "box score" of battles seems rather beside the point.