Before I go into my position, I wanna take a moment to thank whoever my opponent may be.
Marshall Bruce Mathers III was born to Deborah Mathers and Marshall Mathers II on October 17, 1973. At age 9, he heard his first rap song. At 14, he started rapping himself. In 1996, he released Infinite, which bombed, and he received a lot of flack for rapping as a white guy. In 1997, he released The Slim Shady EP (not the LP, the EP), which he introduced the famed Slim Shady. Dr. Dre noticed him, and together, they released The Slim Shady LP. This turned Eminem from an underground act to a celebrity overnight. Fast forward 14 years, several albums, 2 divorces, and 13 Grammys, Eminem is considered by many to be the greatest rapper in the game, me included. If you disagree, let me know.
What the Pro is saying is that if Dr. Dre had not found Marshall B. Mathers lll, he would not have become famous until much later if at all. Also the Pro is basing the debate off of personal opinion. Therefore I'd like that the Pro give actual proof instead of the Pro's personal opinion. I cannot debate further without such information.
If con wishes for actual facts, I will provide some. From 1996 to the present, Em has sold at LEAST 89 million albums. This makes him the best selling rap artist ever, and one of the best selling artists ever. The Slim Shady LP was one of the best selling albums of the 20th century. That says something.
As of 5 days ago, Marshall B. Mathers lll had only sold 35 million units. The Beatles have actually sold 177 million units. That says something. Sure, Marshall may be a good artist, but he probably isn't the best rapper ever.
But the Pro itself did not provide a source... Also if you search "best selling music artists" this site will be the fourth on the Google search. So yes, still no proof that Marshall B. Matters lll is the best rapper to ever live.