One criticism about Josh Bell's game took aim at his SO- and BB-rates. Bell had a 3% BB-rate and a 31.8% SO-rate during his 2012 campaign, a season in which he was 19 and suffered a serious knee injury. Critics used these facts to downgrade Bell's status as a prospect. They claimed he lacked adequate plate discipline and had lost a crucial year of development. Bell fell out of many top-100 prospect lists because of these criticisms.
Bell also seldom walked and often struckout during the early weeks of his 2013 season. He had a BB-rate of 5.3% and a SO-rate of 24.2% on April 26, the day of his 20th game. During spring training, scouts and prospect observers had questioned his tools, including his hit tool, and their reservations seemingly were confirmed by his early struggles.
Bell, it seemed, was on his way to gaining a new label: Bust.
To be sure, you can bet your last dollar that I would not have written this Fanpost if Bell had continued to struggle! As of today, May 28, having played in 48 games, Bell has compiled a 12% BB-rate and a 21.2% SO-rate. It seems his plate discipline is not as faulty as his critics claimed. The following graph clearly depicts his improvements:
The graph makes the convergence of the two series obvious: Bell's BB-rate is increasing and his SO-rate is decreasing.
But this graph does not depict the strength of his improvement in this matter. Consider the following graph, which I generated from continuous 20-game segments of his BB- and SO-rates:
The last 20-game segment is telling: He walked at a rate of 18.4% and struckout at a rate of 16.1%. Not only does this graph make the trend clear, it also depicts the strength of his improvement.
The upshot: Around game 24, Bell began to control the strikezone more effectively than he had at any time since he had become a professional. I would say that Bell has become sufficiently adept at controlling the strikezone that he has put to rest persistent questions about his hit-tool and his capacity to recognize pitches. The ceiling is high; he needs only to achieve it.