Sufficient proof of an anti -doping rule violation under Article 2.1 is established by any of the following: presence of a Prohibited Substance  or its Metabolites  or Markers  in the Rider ’s A Sample  where the Rider  waives analysis of the B Sample and the B Sample  is not analyzed; or, where the Rider ’s B Sample  is analyzed and the analysis of the Rider ’s B Sample confirms the presence of the Prohibited Substance  or its Metabolites  or Markers  found in the Rider ’s A Sample ; or where the Rider ’s A or B Sample  is split into two (2) parts and the analysis of the confirmation part of the split Sample  confirms the presence of the  Prohibited Substance  or its  Metabolites  or Markers  found in the first part of the split Sample  or the Rider  waives analysis of the confirmation part of the split Sample .