1.) The Battle of Brooklyn Heights or the Battle of Long Island

The Victory

The British win a crushing victory, but fail to follow up and end the war.
After the United States declared independence, The british decided to declare un-independance and a series of battles was fought, (mostly losing battles for the USA) and one of the earliest was the Battle of Brooklyn Heights. General William Howe squared of with General George washington on Long Island, outflanking the entire continental army and surrounding both by sea and land. General Howe's command staff wanted him to press forward and take entrenched british positions, but however the english gentlemen set up a siege in hopes that washington would realize he was trapped and surrender. What he didn’t count on was the Americans greatest ability, to run the hell away under the cover of night (which is exactly what they did). The battle was considered a rousing success with General Howe even being given the Order of the Bath by King George the III.

How it lost the war

In all this celebrating, what no one realized was that General Howe's win, was actually a loss as he missed his chance to capture washington and crush the continental army, thus allowing it to continue its war of long boring expensive warfare until the british gave up and went home.

http://www.history.com/this-day-in-history/the-battle-of-brooklyn

2.) The Alamo

The Victory

During the 1835 Texas war of independance from mexico/Rebellious slave owners fighting a battle of irony and freedom, There were several routes into texas and the Alamo was smack dab in the middle of one of them. General Santa Anna attacked the crumbling chapel from 4 sides thoroughly trouncing the 200 defenders, and executing the few survivors.

How it lost the War

It galvanized the other Texans and the mexican forces were said to have lost up to 1600, men that would have been really helpful later during the battle against Sam Houston which the Mexicans lost and Santa Anna was captured. The Mexican army could have easily bypassed the Alamo, or left a token rear guard to seige it, and gone on to defeat Sam Houston.

https://lurj.org/issues/volume-3-number-2/alamo

3.) Napoleon Visits Moscow

The Victory

Everyone knows that you don’t invade Russia in the winter, and that it's always winter in Russia therefore don’t ever invade russia. But Napoleon came close, on September 14th 1812 his 500,00 man french Army pushed and chased Russian forces all the way to moscow then took moscow. Napoleon's conquest of russia had been easy, if it were an action movie an soon to be killed extra would have squinted and said, something doesn’t feel right, just as the aliens attacked.

How it lost the War

The only problem was the one thing Russians care less about that the death of other Russians, it their cities. Napoleon's Army entered an empty city devoid of people to surrender to him, and food. Then sometime during the night it's said that Russians patriots set fire to the city leaving napoleon King of an ash heap with the russian winter and an angry Russian Army following his retreat. Out of 500,000 men it's estimated Napoleon lost 400,00 of them along the retreat. Worst game of Risk ever.

http://www.newworldencyclopedia.org/entry/French_invasion_of_Russia

4.) Chancellorsville

The Victory

Robert E. Lee wins a stunning victory during the civil war by splitting his 60,000 man army against a much larger 80,000 man army lead by General Joseph hooker by breaking the primary rules of warfare at the time and splitting his army to suprise the union troops who were enjoying their numerical superiority and the fact that they had slipped around behind Lee. Lee send Stonewall jackson around to outflank the outflanking and surprised the Union Army routing them back across the Rappahannock. It was considered Lee’s greatest military achievement.

How it lost the war

Lee lost 12,000 casualties that the Rebel army couldn’t really replace but more importantly Lee lost StoneWall Jackson to friendly fire. Upon hearing of Jackson’s death Lee said " I have lost my right arm", and, "I'm bleeding at the heart. Many historians argue that with Jackson still alive Lee could have won at Gettysburg the turning point of the civil war.

https://www.civilwar.org/learn/civil-war/battles/chancellorsville

5.) Verdun

The Victory

The battle of Verdun was one of the longest continuous battles during WWI and is also known for its delicious sugared almonds. This might be why the French fought so hard to keep it. The German army facing an allied army that was getting stronger needed a strategy to end the war quickly. In came the meat Grinder, Verdun was a narrow strip of land with 20 major forts and losing it would be a major blow to the French psyche. General Falkenheim Came up with a plan to lure the French into Verdun and shell them into surrender and domino effect cause the other allies to surrender one by one. The idea was called the Meat grinder and they were going to bleed France white.

How it lost the war

When you stare into the meat grinder it also stares into you. The Germans were too successful in taking parts of verdun and became victims of the very meat grinder they planned to bleed france with. In the end the Germans took many more casualties than they anticipated and ultimately couldn’t keep up with the influx of the British and eventually American troops.
http://www.history.com/news/10-things-you-may-not-know-about-the-battle-of-verdun