further demonstrates just how far his storytelling skills have eroded . 
(ROOT (S (ADVP (RB further)) (VP (VBZ demonstrates) (SBAR (WHADVP (RB just) (WRB how) (RB far)) (S (NP (PRP$ his) (NN storytelling) (NNS skills)) (VP (VBP have) (VP (VBN eroded)))))) (. .)))
(ROOT (S (ADVP (RB )) (VP (VBZ ) (SBAR (WHADVP (RB ) (WRB ) (RB )) (S (NP (PRP$ ) (NN ) (NNS )) (VP (VBP ) (VP (VBN )))))) (. )))