Players With An OPS+ Of 150 Or Higher At Each Of The Following Ages: 20, 21, 22, 23, 24

From the Baseball Reference Play Index. Just Cobb and Trout

Player	OPS+	Year	Age
Ty Cobb	167	1907	20
Ty Cobb	169	1908	21
Ty Cobb	193	1909	22
Ty Cobb	206	1910	23
Ty Cobb	196	1911	24
Mike Trout	168	2012	20
Mike Trout	179	2013	21
Mike Trout	168	2014	22
Mike Trout	176	2015	23
Mike Trout	177	2016	24

Seasons When Two Players Under Age 25 Had 9+ WAR

Data from the Baseball Reference Play Index. This has only happened 7 times, including 2015 & 2016 (an only once between 1912 and 2014 with Mays and Mantle in 1955). If Betts can make it to 10, then we would have only the second time 2 guys made it that high. That won't be easy and, of course, the season is longer than it used to be, so maybe we should use 9.5 for 154 game seasons. That would still be rare.

Player	WAR	Year	Age
Ty Cobb	9.8	1909	22
Eddie Collins	9.7	1909	22
Ty Cobb	10.5	1910	23
Eddie Collins	10.5	1910	23
Ty Cobb	10.7	1911	24
Shoeless Joe Jackson	9.2	1911	23
Tris Speaker	10.1	1912	24
Shoeless Joe Jackson	9.6	1912	24
Mickey Mantle	9.5	1955	23
Willie Mays	9	1955	24
Bryce Harper	9.9	2015	22
Mike Trout	9.4	2015	23
Mike Trout	10.3	2016	24
Mookie Betts	9.5	2016	23

Cubs have allowed an historically low BAbip

Data from the Baseball Reference Play Index. Here are the lowest 25 since 1913

Team	Year	BAbip
CLE	1968	0.244
BAL	1968	0.245
BAL	1969	0.246
BRO	1941	0.249
BAL	1972	0.249
DET	1981	0.249
CHW	1967	0.249
DET	1968	0.250
CLE	1954	0.250
LAD	1975	0.250
NYY	1955	0.251
BRO	1942	0.251
CHW	1966	0.252
CHW	1964	0.252
OAK	1972	0.252
STL	1942	0.252
NYY	1960	0.253
CIN	1942	0.253
MIN	1965	0.254
CIN	1944	0.254
CHC	2016	0.254
CAL	1968	0.254
BAL	1961	0.254
OAK	1970	0.255
BOS	1917	0.255

They are the only team in the top 25 since 1981 (also the only team in the top 50 since 1981). This is probably due to their fielding (they lead the NL in DER with .732). Top 3 teams since 2006 in defensive efficiency rating are the 2016 Cubs .732, 2011 Rays .724, 2013 Reds .715. Cubs might be highest going even farther back but I stopped checking at 2006.

There is usually a pretty high correlation between BAbip allowed and DER for all MLB teams. Here is the correlation in some years

2015) -.97
1960) -.97
1920) -.98

But it was only -.73 in 1913. It was -.89 in 1914. I don't know why it was so low in 1913.

It might be worthwhile to do BAbip relative to the league average. It looks like the other teams on the list are from years that will have a relatively low league BAbip. The 2016 NL is 16th highest since 1913.

Update 9-20-2016: The Cubs are .046 below the league average and that appears to be the best ever (although I was having a bit of a problem for some years in finding the league average using the Excel VLOOKUP tool-if anyone is good at that, please comment here or email me)

Here are the best teams (I think I solved the VLOOKUP issue). Let me know if this formatting does not work. The third number is that team's BAbip allowed, then the league average and then the difference.

Why are the Cubs doing so well? Fielding? Something about their pitchers? Park effects? Just luck?

CHC    2016    0.254    0.300    -0.046
NYY    1939    0.256    0.293    -0.037
SEA    2001    0.262    0.297    -0.035
LAD    1975    0.25    0.284    -0.034
CIN    1999    0.267    0.300    -0.033
OAK    1980    0.258    0.288    -0.03
OAK    1990    0.258    0.287    -0.029
BRO    1941    0.249    0.277    -0.028
BAL    1979    0.258    0.286    -0.028
CHW    1991    0.26    0.288    -0.028
DET    1983    0.258    0.286    -0.028
NYY    1919    0.261    0.289    -0.028

Here is a comment someone left at Fangraphs. See The Most Extraordinary Team Statistic by Jeff Sullivan

"When I saw this headline, I was hoping you’d land on the Cubs’ ability to squash balls in play. But how about these other options for ways to quantify it?

BIP-Wins. Cubs are #1 all-time (since 1871):
http://www.fangraphs.com/leaders.aspx?pos=all&stats=pit&lg=all&qual=0&type=6&season=2016&month=0&season1=1871&ind=1&team=0,ts&rost=0&age=0&filter=&players=0&sort=4,d

…and they have derived 9.5 more wins from this ability than the #2 team this season:

http://www.fangraphs.com/leaders.aspx?pos=all&stats=pit&lg=all&qual=0&type=6&season=2016&month=0&season1=2016&ind=1&team=0,ts&rost=0&age=0&filter=&players=0&sort=4,d

BP’s Park-Adjusted Defensive Efficiency. The 2016 Cubs are #1 by a wide margin, but this stat only goes back to 1950:

http://www.baseballprospectus.com/sortable/index.php?cid=1960231

OPS+ allowed. B-R only has solid data going back to 1923 for this stat. During that period, the 2016 Cubs are #1 by three percentage points:

http://bbref.com/pi/shareit/HKbXG"

Trout Now Leads In WAR Through Age 24

Here is the top 10

Rk	Player	WAR
1	Mike Trout	46.9
2	Ty Cobb	46.7
3	Mickey Mantle	40.9
4	Alex Rodriguez	38
5	Ken Griffey	37
6	Mel Ott	36.8
7	Rogers Hornsby	36.1
8	Jimmie Foxx	36
9	Arky Vaughan	34.3
10	Ted Williams	34.2

Now the leaders in WAR per 648 plate appearances for everyone with 20+ WAR through age 24. It looks like the WAR for Ruth does not include pitching.

Rk	Player	WAR	PA	Per 648PA
1	Babe Ruth	20.2	1332	9.83
2	Mike Trout	46.9	3441	8.83
3	Ted Williams	34.2	2613	8.48
4	Willie Mays	24.8	1978	8.12
5	Ty Cobb	46.7	3730	8.11
6	Rogers Hornsby	36.1	2902	8.06
7	Stan Musial	24	1953	7.96
8	Eddie Collins	28.1	2312	7.88
9	Mickey Mantle	40.9	3491	7.59
10	Tris Speaker	30.1	2623	7.44
11	Lou Gehrig	22.3	1952	7.40
12	Dick Allen	22.7	2040	7.21
13	Jimmie Foxx	36	3270	7.13
14	Alex Rodriguez	38	3515	7.01
15	Arky Vaughan	34.3	3180	6.99
16	Albert Pujols	29.2	2728	6.94
17	Joe DiMaggio	26.3	2545	6.70
18	Ken Griffey	37	3606	6.65
19	Eddie Mathews	31.5	3141	6.50
20	Barry Bonds	23.4	2388	6.35
21	Cal Ripken	27.9	2855	6.33
22	Rickey Henderson	28.1	2891	6.30
23	Johnny Bench	30.7	3229	6.16
24	Hank Aaron	29.9	3173	6.11
25	Frank Robinson	29.7	3155	6.10