By the numbers: Chances the Bulls get to the Finals with a healthy D-Rose
18 and 9. That’s all people kept saying when Derrick Rose’s MRI revealed a torn ACL. 18 and 9. If we can win in the regular season without him, we should have no problem winning in the playoffs without him, right? Wrong. Dead wrong. It’s okay to remain hopeful as a fan. It’s what keeps us, as sports fans, going in life. But any sensible basketball fan knew that our season was pretty much over when Rose hit the floor untouched. Then it got me thinking: what are the chances the Bulls would have gotten to NBA Finals with a healthy Derrick Rose?
In order to figure this out, I used Excel Solver to power rate every NBA team during the regular season and playoffs from using season-long data from nba-reference.com. Using every single score from Christmas Day until the final day of the season, I calculated the home team’s margin, prediction of each game, and the squared error of each game, which equals (home margin – prediction)^2. The sum of the squared error acts as the target cell and must be minimized in order to come up with accurate team ratings. Assuming that the average NBA team has a rating of 0, you can see that home teams had an edge of 2.82 points per game during the regular season as well as throughout the ongoing playoffs. The Bulls had the highest rating of 7.426 (just edging out the Spurs at 7.277). This means that they were 7.426 points better than the average NBA team, and over 20 points better than the lowly Bobcats, which is just stupid. The same process was followed in order to come up with team ratings during this season’s playoffs. These ratings were used for the Celtics (3.25) and Heat (7.25) because they both tend to coast throughout the regular season, whereas the Bulls go balls through the walls night in and night out. Below is a snapshot of each team’s rating (regular season and playoffs).
Now the fun part: calculating our chances of beating Philadelphia, Boston and Miami with a healthy Derrick Rose using @Risk. The first step was forecasting the average scoring margin for home and away games. For home games, I took (Home Edge + Bulls Rating – Away Team Rating). The projected margin was then calculated using the average forecast and standard deviation (the book Mathletics states that “12 points is the historical standard deviation of actual scores about a prediction from a ranking system”). If that number is greater than 0, then the Bulls will be given a 1 (indicating they won) and will be given a 0 if the number is less than 0 (indicating they lost). If the sum of the wins is greater than or equal to 4, then the Bulls would win the series.
First up was Philadelphia. After running 1000 iterations, the Bulls won the series 769 times, meaning they had a 76.9% chance of beating the Sixers in the first round with a healthy Rose. And without Rose… well, we can all just agree that the probability was probably not even 10% given the way we’ve looked. Ew.
Next up was Boston. We had a 79.2% chance of beating them based on the Celtics’ current level of play in the playoffs.
Finally, Miami. It pains me to say this, but given how we played during the regular season (remember, we played 27 games without Rose, too), and given how Miami has played against the Knicks thus far (which is incredible to say the least), the Bulls had a 53% chance of winning the series and moving on to the Finals.
Who really knows what would’ve happened if the Rose didn’t tear his ACL? Coming up with probabilities is fun and everything, but it’s not a final indicator of who would actually win the series. The games still have to be played. That’s why it hurts to not see it happen. We’ve all dreamed about the 2012 Eastern Conference Final rematch with Miami since last May, yet it all fell apart so fast. All we can do is hope our boys get healthy and come back strong sooner rather than later.