General Vasily Chuikov came up with this name to describe a soldier's adaptation to the tactics that led to survival in the Battle of Stalingrad. Graduates stood a chance of surviving one of the most brutal and grinding battles in history; slow learners all died. The Germans called the style of battle Rattenkrieg, or rat war. All told, Stalingrad cost an estimated 1.5 million lives.

Chuikov, the commander of the Soviet 62nd Army, had operational command of the defensive effort at the city named after Soviet dictator Josef Stalin in the fall of 1942 and winter of 1943. Attacking from the west, the German invaders came within a few hundred yards of the Volga River that marked Stalingrad's eastern border, but a combination of luck, Adolf Hitler's hubris, Chuikov's tactical skill, and the Soviet system's willingness to throw hundreds of thousands of their own of soldiers' lives at the German forces led the Wehrmacht and the Red Army to a stalemate in the ruined city. The stalemate was broken by a daring Soviet pincer attack in midwinter, west of the city, that cut off the German 6th Army in Stalingrad and its outskirts; ultimately, the 6th Army was destroyed and the remaining Germans driven back in the first really successful Soviet counterattack of World War II.

But before that happened, Chuikov fought the Germans to a standstill. These were the essentials of the tactical lessons he and his troops learned in the battle.

Use wreckage to your advantage

Self-propelled artillery (big guns on treads) and, particularly, tanks were key to Nazi Germany's early successes in World War II. They could mount fast-moving, devastating attacks on less agile enemy units, breaking through the opposing lines and encircling the soldiers who manned them. Such tactics worked best in fields and on the open steppe of the western Soviet Union; they were almost useless amid the collapsed walls and blocked roads inside Stalingrad.

When defending against an attack by German armour, Chuikov ordered his troops, stay hidden behind rubble until the enemy tanks are right in front of you. If possible, booby-trap tank routes to seal them off once enemy tanks are already committed to the battle, so they can't move or retreat.

The Soviets learned to attack tanks from above, on building floors higher than their turrets could aim. They blew holes in the walls of cellars for added manouvrability. They threw grenades onto the floors above German defenders, bringing stone ceilings down upon them.

Dig in close to enemy positions

Another of the Germans' major technological advantages was the Luftwaffe, which could swoop in with dozens or hundreds of planes to "soften up" targets with bombs and strafing attacks long before a German infantryman even put his boots on.

Chuikov ordered his soldiers to set up as close to the Germans as possible, sometimes mere yards away, so any German air attack would kill as many Germans as Soviets.

Keep moving

German soldiers' gear -- steel helmets, steel-shod boots -- was heavy; the Wehrmacht depended on vehicles when it needed to move quickly. Chuikov's troops could turn their relative lack of equipment to their advantage by staying on the move at all times, attacking from unexpected angles and denying German guns stationary targets. He also advised his troops to move on all fours most of the time and on their bellies if necessary, both for cover and for stability in the rubble.

Shoot first and constantly

The Soviets had no shortage of ammunition and Chuikov told his troops to use whatever they needed. He issued as many submachine guns as he could get, hoping to get one in the hands of every soldier (instead of into one out of every five or six as had been standard). The Soviets threw grenades into any room, cellar, or rubble-cave of which they were even slightly suspicious, since gratuitous rubble worked to their advantage. Chuikov's "hand-grenade rule" held that no soldier should move without throwing a grenade first, and never move farther at a time than he could throw another one. His troops used flamethrowers without hesitation.

They also attacked at night, when the Luftwaffe was of even less use to the Germans. The Soviets aimed to deny the Germans sleep and comfort, in addition to the tactical advantage.

Forget conventional units

Chuikov dispensed with conventional notions of platoons and companies, creating a unit called a "shock group." One shock group included three sub-units: a storm group, a reinforcement group, and a reserve group, in a structure intended to take advantage of the tactics already described. The storm group had eight to ten soldiers, armed with machine guns, grenades, daggers and shovels (used as axes or clubs as necessary). Its task -- usually starting from a very close position -- was to hit the enemy hard and fast, attacking silently and with no artillery salvo. Once the advantage of surprise was used up, they'd use a flare to signal for the reinforcements to mop up the survivors, and bring in the reserve as necessary.

The key was speed. The entire attack, from first assault to consolidation of the position, was supposed to take only three minutes.

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These days, such urban-warfare tactics seem almost trivial, but World War II was the first war to feature both explosive munitions and large-scale fighting in city streets. In 1942, this was all new. Given the importance of the Battle of Stalingrad in turning the tide, it's no exaggeration to say that the training at Chuikov's Stalingrad Academy of Street-fighting was vital to the Allies' defeat of the Germans in World War II.

Chuikov was also on the scene as the Soviets blasted their way into Berlin in the early spring of 1945, and veterans of the Battle of Stalingrad were instrumental in taking the German capital.

Back in Stalingrad, it wasn't long before the academy metaphor had achieved a certain grim literalness: soldiers on launches crossing the Volga into perhaps the closest thing to Hell yet seen on Earth were given a physical piece of paper with the lessons summarized on it. This was their training, these green officer cadets, these boys drafted from hardscrabble farms in Kazakhstan, these sailors transferred from their ships in Vladivostok. Crawl fast, shoot whenever possible, sneak up and club with a shovel when necessary. Not one step back. Now go.