According to one scholar, Richard Strebel, the foundation for modern fighting dogs came from: 1. The Tibetan Mastiff; 2. The English Mastiff, out of which came the French Mastiff, the English Bulldog, and the Pug; 3. The Great Dane, out of which came the Danish Mastiff and the Boxer; 4. The Newfoundland; and 5. The Saint Bernard, out of which came the Leonberger.[8] However, Dieter Fleig disagreed with Strebel and offered the following list as composing of the foundation for modern fighting dogs: 1. The Tibetan Mastiff; 2. The Molossus; 3. The Bull Biter; 4. The Great Dane; 5. The English Mastiff; 6. The Bulldog; 5. The Bull and Terrier; and 6. The Chincha Bulldog.[8]