Hear about basketball, what's your first thought?

一講到籃球，你會想到甚麼呢？球衣、球鞋，還是……

Jersey? Basketball shoes? Or...

是的，我們要介紹的便與美國NBA的球員市場有關。

yes, the topic is about the market of the NBA basketball players

首先要從西元1989年說起，當FIBA，

First of all, we will start from 1989

也就是國際籃球聯合會投票消除業餘與專業運動員之間的差別，

when FIBA, the Fédération Internationale de Basketball

並使得非美國的球員能夠在不取消國家隊資格的情況下，來到NBA打球。

voted to eliminate the distinction between amateurs and professionals.

然而由於觀察的時間有限及統計數據蒐集不足，在資訊不對稱的情況下，

This ruling meant that international players could play in the NBA

可能使得球員的薪水與其表現不相符合。

without being disqualified from representing their countries in the world competitions

也就是說，他拿到了高出其實際應得的薪水。

and thus started the flow of international players into the NBA

Kwame Brown即是最好的例子。

But due to the limited time and the lack of stats, under the condition of information asymmetry

這個現象就是贏家的詛咒。

it would make the players' salaries are not consistent with their performance

贏家的詛咒，會出現在球團，對於球員的價值不確定時，

It means the salaries are higher than the players should have been

可能因為過度樂觀，或是統計數據蒐集不足等因素，而對於球員的價值估計過高，而遭受損失。

after accounting for their personal characteristics and on-court performance in the previous season.

另一可能原因，當球員價值不易確定時，

The best example is Kwame Brown.

若價值估計十分正確，往往無法在有其他競爭者的條件下得標；

And this phenomenon is called the “winner’s curse”

而若價值估計過高，可能得標，卻也很可能同時遭受損失。

The winner's curse appears when the player's value can't be accounted properly.

為了消除此現象，球團開始估計球員的邊際收益生產量。

Because of excessive optimism or the lack of stats,

他們會根據與球員相關的特性來評估，如在賽季的得分、籃板、助攻，

the team will overestimate the player’s value, and then suffers loss

以及球員本身經驗、年齡、身高等等，

Another possible reason is when the player’s value is not easy to account.

並且球團也會根據其人氣等做為考慮因素。

If estimate correctly, the team may lose the bid

但在此次的介紹裡，我們主要以球員在賽季中的表現為主，

and if overestimate, the team may win the bid, but also get some loss.

將所有球員區分為鋒線，包含後衛、小前鋒，及禁區，包含大前鋒、中鋒，

The disappearance of the premium paid is attributed to estimate the Marginal Revenue Product

並根據其數據表現，判斷出何項統計數據最能影響球員的薪資。

The team can look at the performance to evaluate the players.

我們在許多數據中，選擇了幾個覺得對薪水高低影響程度較大的來做研究：

For example, a team might look at the points scored, total rebounds, and assists.

鋒線選擇了6個數據，而禁區的研究數據有5個。

And plus the experience, age, height, and etc.

那麼，我們在探討數據與薪水高低的影響程度前，

Further, a team might also look at how the public will embrace a given player as a predictor of his drawing power.

先詢問球迷們認為哪項數據影響鋒線球員和禁區球員的薪水高低相關程度較高。

But in this video we will focus on the player's performance in the seasons.

鋒線球員部分，最高的是PTS 其次是AST 3P% ;

Divide all the players into two parts

禁區球員，前三為REB、BLK、FT%。

the first we call it the backcourt which includes the guards, and the small forward

讓我們來看看研究結果與球迷們心中所想的是否一致。

The second is called the frontline including the power forward and the center.

首先，找出2003~2014年，各年份排名前一百名薪水的球員，

And then we will determine which stats are the most relative with the players’ salaries

並依年份薪水的高低以及鋒線禁區做分類及排序

In our research, we choose some of the stats, which are influential to wages.

第二步，用相關係數看影響程度。

There are six stats when it comes to the backcourt, and five stats for the frontline.

我們使用excel，驗證各數據與薪水的關聯性再計算各數據與薪水的相關程度。

Before we start our analysis and discussion

並設定在t檢定95%的信心水準之下

we first inquire of the fans which factor correlate to wages the most.

並得知數據與薪水有相關

For the backcourt players, top three are PTS, AST and 3P%.

第三步，總結和各數據計算出來的結果。

And for the frontline players, REB, BLK and FT% stands out.

鋒線球員部分，主觀觀點中，

Then, let’s move on to see if the results to our research and the perspectives from the fans are identical.

影響薪資的前三數據分別是PTS、AST、3P%；

First of all, we list the top 100 players who got the highest salary during the years 2003~2014 individually

而客觀觀點中，前三是PTS、AST、+/-。

And we rank and classify those players by the amount of their wages, the backcourt and the frontline

主觀認知與客觀結果較不同的是--三分球命中率。

Next, we apply correlation coefficient to check the impact on each other.

我們認為，三分球是近兩年隨著金洲勇士隊竄起而興盛起來的，

That is, we calculate the relevant level between each datum and wages by EXCEL.

對球迷來說，球員之間三分球的較量是能夠增加比賽可看性和精采度的。

And conduct a hypothesis test to clarify if there is actual relation between wages and each datum.

而過去的比賽形式以及三分球的風行程度並不同於這兩年。

We’ll do so by using a t-test with a confidence level of 95%.

禁區部分，主觀認為前三是REB、BLK、FT%；

Then we can find that both stats and wages are related.

而客觀觀點前三是PTS、+/-、REB。

Lastly, we’ll draw a proper conclusion.

我們推論，球迷對於一場好看的比賽的預期，

For the backcourt players, in the subjective viewpoint,

反映在他們對於不同角色的球員的期望表現上，

the top three stats which are influential to the wage are PTS, AST and 3P%.

自然認為籃板數目之於禁區是非常重要的。

And in the objective viewpoint, PTS, AST and +/- stands out.

而NBA是商業化很高的職業運動，

We can find that the 3P% is the most different thing

為了吸引更多觀眾創造更大的商機，他們會將與得分相關的數據納入薪資的優先考量，

between the subjective and the objective data.

畢竟比賽的輸贏終究回歸到比數上。

We infer that the Golden State Warriors went viral caused three point field goal prevails in the NBA.

因此，客觀數據的統計上便反映出和主觀認知上的落差。

For the fans, competition of three point field goal between the players

感謝您的收看！

definitely adds more excitement to the games.

However, the three point field goal didn’t prevail in the period of the data we test.

For the frontline players, in the subjective viewpoint,

the top three stats which are influential to the wages are REB, BLK and FT%.

And in the objective viewpoint, PTS, +/- and REB stands out.

We can infer that the fans’ expectation of a worth watching game,

which will reflect on their anticipative performance of a player.

So, they believe that the rebounds are important to the frontline.

However, NBA is a professional but commercial league.

In order to attract more spectators to create more business opportunity,

the team will take the data correlate to score into consideration primarily

After all, the win and lose of a game are result from the point.

Therefore, the objective stats indicate some differences against the subjective viewpoint.

Thanks for your watching.