Attempting to project career totals of any stat is definitely a risky thing to do, but I've been messing around with some numbers and an Excel spreadsheet to see what kind of home run progression trend we can expect for Chris Davis' immediate and long term future.
In the minors Davis had an extremely low plate appearances per home run rate, so it's been difficult to find comparable hitters to measure him against. But I think if we use a moderate range of hitters and look at their home run progression trends, maybe we can draw some conclusions about where Davis might end up over the next 10 years in terms of home run production.
As I said, Davis' power rates are quite a bit better than most of the comparable hitters I found to compare him with, but he does match up well with Albert Belle and Cecil Fielder in terms of his overall stats. I guess we could think of Davis as either a more advanced Ryan Howard or a more powerful Albert Belle. Either way, he matches up well against some of the elite power hitters of the past 20 years, and could arguably end up with a higher sustained home run production level than any of them.
While numbers can give us an idea about where Davis fits in with other hitters, I think a visual representation of the trend lines established by each of the above hitters would help us see what level of production we can expect from Davis in the future. The following chart represents the average plate appearances per home run for each of the hitters in the chart above.
There's a lot of stuff going on in this graph, so I'll take some time to explain what it all means. The colored lines represent each hitters actual production. The thin black lines represent their general trend lines over time, meaning that it follows their average change in production rates as they age. The numbers at the bottom of the graph are the actual PA/HR averages for each player between the ages of 20 and 30 years old.
From the numbers given, we can see that these hitters began to approach their minor league home runs rates around the age of 24 or 25 years old. They all tend to follow a general trend of progression, with their highest levels of production coming between the ages of 25 and 29 years old.
Now let's look at those same stats translated into projected season totals if each player were to accumulate 650 plate appearances per season.
Once again, it's a very busy chart, but the overall trend is obvious. Each hitters prime production levels occurred between the ages of 25 and 29, with averages consistently in the 40 to 50 home run range per season. Of the 5 hitters, Rob Deer is the odd man out with production levels floating around 30 home runs per season. As a side note, Ryan Howard's trend line is severely steep, and may be inaccurate due to not having more than 3 years of major league stats. Then again, it could be a very accurate representation of his past and future regression rates, meaning that he could drop off the face of the planet in terms of home run production over the next few years.
With the general trends we established above, let's narrow down our focus to hitters that Chris Davis most resembles, namely Albert Belle, Cecil Fielder, and Ryan Howard. We'll take the regression and progression rates of each of the 3 hitters as set out by our above chart, and then apply those same trends to Chris Davis' minor league numbers to see what we can come up with.
By applying the trends we established above, Davis should reach his minor league home run production rate at about the age of 24 or 25 years old. To be conservative I've set his PA/HR rate to his minor league rate at the age of 25. After the age of 25, each comparable hitter improved on their home run rate until they reached approximately a rate of 12.5 PA/HR around the age of 26 or 27, which I also applied to Davis' numbers. By the age of 29 or 30 each hitter had steadily regressed back to their minor league production rates, so I've also applied that trend to Davis' projected production.
Here are Davis' projected yearly home run totals according to the values predicted in the above chart.
While most hitters don't really follow a smooth production course like I have predicted for Davis, the purpose of the above chart is to give an us an idea about what Davis' potential is over the next 8-10 years. There's no guarantee that he will actually follow my projections, but the numbers suggest that he'll be somewhere in the same ballpark. If he does happen to follow my projections, depending on how long he plays he could have 400-500 home runs by the end of his career, which would put him in some good company. Albert Belle and Cecil Fielder retired with 389 and 319 home runs respectively (Fielder played in Japan at 25, thus losing out on perhaps an extra 40 home runs), so these projections for Davis seem reasonable.
Low end career projection: 350 HR
Mid-range projection: 400 HR
High end projection: 450+ HR