The Bulge. As stated a quick thrust in bad weather to reach the coast,200 miles away, cutting though 500,000 local Allies by 250,000 Axis. 5 million German gallons of gas available but about 2 million made it to the battle. And the north flank blitzed past 1 million US Army gallons at Stavelot, where it was really needed. As German army drove deeper it was checked much of the time by US Army blowing bridges over the many rivers encountered, or stubborn resistance by pockets of US soldiers. Patton braged he would be there in 48 hrs, but really took 5 days for his armor to break through German defenses. Some German soldiers achieved great victory like Sgt Barkmann, who took out 3 Shermans with his Panther, crushed an MP's jeep who had ordered him to halt. Sped past hundreds of soldiers untouched, then came to 9 Shermans in a row. He knocked out one, and the remaining crews abandoned their tanks for the woods.German Grenadeirs took care of the rest. Speeding deeper he found more Shermans parked unattended but drove on past, took out 3 more Shermans then hid in the woods. But other German soldiers surrendered without a fight. German airborne of 1,200 were dropped all over the front. 150 assembled at the highway north of Melmedy, as ordered, and did nothing while 3 US divisions rolled past for 3 days. The US army did rally quickly, and hundreds of Panzers ran out of gas.
Could the battle been a German victory? Yes with enough gas,but everyone agrees these 25 weak divisions would have been later crushed over time by the remaining US 75 divisions followed by 30 Brit/Canadian divisions, and 14,000 fighter bombers in the air.
In the 6 weeks, US Army 108,000 casualties, Brits 3,000, German army 100,000. However Battle of the Bulge was total American victory as they stopped a penetration of about 30 miles and no deeper than 70. Then pushed the enemy back beyond it's starting line. It was America's Battle, and they did well.