Lineage is a funny thing. The idea of an unbroken line of transmission reaching back to the original source can be appealing for some. This distinction can hold value but can also lead people astray into either overvaluing its importance or disregarding its import entirely. Who you learned from can be important for transmission of knowledge. It's nigh impossible to have someone teach you a technique or concept who doesn't themselves know it. It's also a stylistic indicator, that is, student will always have influence on their tactics and movement patterns. Even in more modern and competitive martial arts like BJJ or Muay Thai, who you trained and graded under is often a caveat to the belt around your waist because the quality of training, success in application, and qualifications for success all vary, and increase in variation as generations pass. Here one of the big problems start to rear their head. Let's take a single progenitor of a style or offshoot of a style. In generation 1 each of the students can have vastly different experiences from how long they stay and train, the intensity of their training and gradings, and the content of their instruction, their closeness to the instructor. Each of these can vary based on the instructor, the individual, and the conditions around training. Students often make the mistake of thinking that simply because two people trained under the same instructor, even during the same time period, that they received the same quality of instruction or training. People may even go so far as to try and use an instructor's fame for themselves. Students who may have rarely or never trained with an instructor may pass themselves off as students, or equal students, through photos of themselves with said instructor. This mirelurk of complications only becomes more difficult to untangle as years pass and even legitimate instructors may take advantage of the shroud time casts as a way to hide their faults and inflate their credibility. So how can a student use lineage to judge prospective instructors? I would suggest 4 things: Lineage can never be a major determinant of skill on its own. Not everyone who learns from a good instructor will be one themselves. Where possible try to use a more empirical method of determining skill like success in resistant, competitive formats. Try to compare technique of the instructor considered, to their classmates (successful in #2 if possible), especially in their earliest available exposure as an instructor. Similar technique and explanations for technique, to both to their instructor and fellow (quality) students, is a good sign. Try to figure out how personally close an instructor was to their instructor. People are more willing to share openly with people they're close to rather than people who simply pay $$$, this includes martial arts instructors. Lineage can be a tool in determining the potential for the amount and quality of information you're likely to be in for training under a particular instructor, but like any tool it can fail. Learning to fight and test your skills in resistant formats keeps you from falling into the "classical mess" of blind adherence to tradition, and actually prepare yourself better to be able to assess the possible utility of what is being handed down by a certain tradition. Never rely on lineage alone as a marker of quality but let it inform your selection of instructor.