Krages chose his racing pseudonym specifically to prevent his mother from discovering what she might consider a dangerous hobby. He made his competitive debut in a Porsche 911 in 1976, later competing in the Deutsche Automobil Rundstrecken Serie (DARS), where he collected several podium finishes. He joined the more prestigious Deutsche Rennsport Meisterschaft (DRM) in 1978, the same year he made his debuts at both the 24 Hours of Daytona and the 24 Hours of Le Mans.
Through the early 1980s, Krages maintained sporadic racing commitments in the DRM and World Sportscar Championship, typically entering as a privateer. In 1984, he drove alongside friend and team owner Dieter Schornstein in a Group C Porsche 956 for a significant portion of the World Sportscar Championship season, including at Le Mans.
The defining moment of Krages's career came at the 1985 24 Hours of Le Mans, when he and teammates Klaus Ludwig and Paolo Barilla won the race for Joest Racing in a Porsche 956, competing under the John Winter alias. His contribution was a single stint in the early hours of Sunday morning, most of it run under safety car conditions — a modest role in the actual driving, but a share in a historic victory nonetheless.
The pseudonym's secret did not survive the win. After the podium ceremony, Krages's mother picked up a newspaper the following morning and saw a photograph of her son on the rostrum. Rather than objecting, she encouraged him to continue racing — the opposite of what Krages had feared all along.
In 1986, Krages took the German Interserie title, usually racing privately entered Porsches. He returned to Le Mans that year to defend his title alongside Ludwig and Barilla, but an engine failure ended their race. Over the course of his career, Krages started at Le Mans ten times, with his best subsequent result a third-place finish in 1988 driving a Joest Racing Porsche 962. He also claimed victory at the 24 Hours of Daytona in 1991 for Joest in the same car.
His career extended into IMSA GTP competition until 1993, when he won at Road America with Manuel Reuter in the final season before the series ended. In 1994, Krages transitioned to the Deutsche Tourenwagen Meisterschaft (DTM) driving an Opel Calibra. At AVUS that season he was involved in a severe accident in which his car was engulfed in a fireball. He returned for 1995 under his real name in a privateer Mercedes-Benz C-Class, scoring points at the Norisring, but that proved to be his final season of competition.
After retiring from racing, Krages sold his business interests and emigrated to Atlanta, Georgia, where he started a toy business. Struggling with business difficulties and depression, he died by suicide on 11 January 2001.
Louis Krages remains a singular figure in motorsport — a wealthy amateur who reached the highest level of endurance racing while going to extraordinary lengths to conceal it, winning one of the world's most prestigious races under an assumed name. The 1985 Le Mans victory placed him, as John Winter, among an elite group of amateur drivers to have won outright at the Circuit de la Sarthe.