rowing stroke
...that the two fundamental reference points in the rowing stroke are the catch where the oar blade is placed in the water, and the extraction (also known as the 'finish' or the 'release') where the oar blade is removed from the water?
...that the two fundamental reference points in the <b id="mwAwU"><a class="mw-redirect" href="./Anatomy_of_a_stroke" id="mwAwY" rel="mw:WikiLink" title="Anatomy of a stroke">rowing stroke</a></b> are the catch where the <a href="./Oar_(sport_rowing)" id="mwAwc" rel="mw:WikiLink" title="Oar (sport rowing)">oar</a> blade is placed in the <a href="./Water" id="mwAwg" rel="mw:WikiLink" title="Water">water</a>, and the extraction (also known as the 'finish' or the 'release') where the oar blade is removed from the water?